1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.10
6 * Support for tracepoints on aarch64-linux was added in GDBserver.
8 * The 'record instruction-history' command now indicates speculative execution
9 when using the Intel(R) Processor Trace recording format.
11 * GDB now allows users to specify explicit locations, bypassing
12 the linespec parser. This feature is also available to GDB/MI
17 maint set target-non-stop (on|off|auto)
18 maint show target-non-stop
19 Control whether GDB targets always operate in non-stop mode even if
20 "set non-stop" is "off". The default is "auto", meaning non-stop
21 mode is enabled if supported by the target.
24 maint show bfd-sharing
25 Control the reuse of bfd objects.
29 Control display of debugging info regarding bfd caching.
31 set remote multiprocess-extensions-packet
32 show remote multiprocess-extensions-packet
33 Set/show the use of the remote protocol multiprocess extensions.
35 * The "disassemble" command accepts a new modifier: /s.
36 It prints mixed source+disassembly like /m with two differences:
37 - disassembled instructions are now printed in program order, and
38 - and source for all relevant files is now printed.
39 The "/m" option is now considered deprecated: its "source-centric"
40 output hasn't proved useful in practice.
42 * Support for various ROM monitors has been removed:
44 target dbug dBUG ROM monitor for Motorola ColdFire
45 target picobug Motorola picobug monitor
46 target dink32 DINK32 ROM monitor for PowerPC
47 target m32r Renesas M32R/D ROM monitor
48 target mon2000 mon2000 ROM monitor
49 target ppcbug PPCBUG ROM monitor for PowerPC
51 * Support for reading/writing memory and extracting values on architectures
52 whose memory is addressable in units of any integral multiple of 8 bits.
54 *** Changes in GDB 7.10
56 * Support for process record-replay and reverse debugging on aarch64*-linux*
57 targets has been added. GDB now supports recording of A64 instruction set
58 including advance SIMD instructions.
60 * Support for Sun's version of the "stabs" debug file format has been removed.
62 * GDB now honors the content of the file /proc/PID/coredump_filter
63 (PID is the process ID) on GNU/Linux systems. This file can be used
64 to specify the types of memory mappings that will be included in a
65 corefile. For more information, please refer to the manual page of
66 "core(5)". GDB also has a new command: "set use-coredump-filter
67 on|off". It allows to set whether GDB will read the content of the
68 /proc/PID/coredump_filter file when generating a corefile.
70 * The "info os" command on GNU/Linux can now display information on
72 "info os cpus" Listing of all cpus/cores on the system
74 * GDB has two new commands: "set serial parity odd|even|none" and
75 "show serial parity". These allows to set or show parity for the
78 * The "info source" command now displays the producer string if it was
79 present in the debug info. This typically includes the compiler version
80 and may include things like its command line arguments.
82 * The "info dll", an alias of the "info sharedlibrary" command,
83 is now available on all platforms.
85 * Directory names supplied to the "set sysroot" commands may be
86 prefixed with "target:" to tell GDB to access shared libraries from
87 the target system, be it local or remote. This replaces the prefix
88 "remote:". The default sysroot has been changed from "" to
89 "target:". "remote:" is automatically converted to "target:" for
90 backward compatibility.
92 * The system root specified by "set sysroot" will be prepended to the
93 filename of the main executable (if reported to GDB as absolute by
94 the operating system) when starting processes remotely, and when
95 attaching to already-running local or remote processes.
97 * GDB now supports automatic location and retrieval of executable
98 files from remote targets. Remote debugging can now be initiated
99 using only a "target remote" or "target extended-remote" command
100 (no "set sysroot" or "file" commands are required). See "New remote
103 * The "dump" command now supports verilog hex format.
105 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
107 * On GNU/Linux, GDB and gdbserver are now able to access executable
108 and shared library files without a "set sysroot" command when
109 attaching to processes running in different mount namespaces from
110 the debugger. This makes it possible to attach to processes in
111 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
112 See "New remote packets" below.
114 * The "tui reg" command now provides completion for all of the
115 available register groups, including target specific groups.
117 * The HISTSIZE environment variable is no longer read when determining
118 the size of GDB's command history. GDB now instead reads the dedicated
119 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
120 disables truncation of command history. Non-numeric values of GDBHISTSIZE
125 ** Memory ports can now be unbuffered.
129 ** gdb.Objfile objects have a new attribute "username",
130 which is the name of the objfile as specified by the user,
131 without, for example, resolving symlinks.
132 ** You can now write frame unwinders in Python.
133 ** gdb.Type objects have a new method "optimized_out",
134 returning optimized out gdb.Value instance of this type.
135 ** gdb.Value objects have new methods "reference_value" and
136 "const_value" which return a reference to the value and a
137 "const" version of the value respectively.
141 maint print symbol-cache
142 Print the contents of the symbol cache.
144 maint print symbol-cache-statistics
145 Print statistics of symbol cache usage.
147 maint flush-symbol-cache
148 Flush the contents of the symbol cache.
150 maint set target-non-stop (on|off|auto)
151 maint show target-non-stop
152 Control whether GDB targets always operate in non-stop mode even if
153 "set non-stop" is "off". The default is "auto", meaning non-stop
154 mode is enabled if supported by the target.
158 Start branch trace recording using Branch Trace Store (BTS) format.
161 Evaluate expression by using the compiler and print result.
165 Explicit commands for enabling and disabling tui mode.
168 set mpx bound on i386 and amd64
169 Support for bound table investigation on Intel(R) MPX enabled applications.
173 Start branch trace recording using Intel(R) Processor Trace format.
176 Print information about branch tracing internals.
178 maint btrace packet-history
179 Print the raw branch tracing data.
181 maint btrace clear-packet-history
182 Discard the stored raw branch tracing data.
185 Discard all branch tracing data. It will be fetched and processed
186 anew by the next "record" command.
191 Renamed from "set debug dwarf2-die".
193 Renamed from "show debug dwarf2-die".
196 Renamed from "set debug dwarf2-read".
197 show debug dwarf-read
198 Renamed from "show debug dwarf2-read".
200 maint set dwarf always-disassemble
201 Renamed from "maint set dwarf2 always-disassemble".
202 maint show dwarf always-disassemble
203 Renamed from "maint show dwarf2 always-disassemble".
205 maint set dwarf max-cache-age
206 Renamed from "maint set dwarf2 max-cache-age".
207 maint show dwarf max-cache-age
208 Renamed from "maint show dwarf2 max-cache-age".
211 show debug dwarf-line
212 Control display of debugging info regarding DWARF line processing.
216 Set the maximum number of candidates to be considered during
217 completion. The default value is 200. This limit allows GDB
218 to avoid generating large completion lists, the computation of
219 which can cause the debugger to become temporarily unresponsive.
221 set history remove-duplicates
222 show history remove-duplicates
223 Control the removal of duplicate history entries.
225 maint set symbol-cache-size
226 maint show symbol-cache-size
227 Control the size of the symbol cache.
229 set|show record btrace bts buffer-size
230 Set and show the size of the ring buffer used for branch tracing in
232 The obtained size may differ from the requested size. Use "info
233 record" to see the obtained buffer size.
235 set debug linux-namespaces
236 show debug linux-namespaces
237 Control display of debugging info regarding Linux namespaces.
239 set|show record btrace pt buffer-size
240 Set and show the size of the ring buffer used for branch tracing in
241 Intel(R) Processor Trace format.
242 The obtained size may differ from the requested size. Use "info
243 record" to see the obtained buffer size.
245 maint set|show btrace pt skip-pad
246 Set and show whether PAD packets are skipped when computing the
249 * The command 'thread apply all' can now support new option '-ascending'
250 to call its specified command for all threads in ascending order.
252 * Python/Guile scripting
254 ** GDB now supports auto-loading of Python/Guile scripts contained in the
255 special section named `.debug_gdb_scripts'.
259 qXfer:btrace-conf:read
260 Return the branch trace configuration for the current thread.
262 Qbtrace-conf:bts:size
263 Set the requested ring buffer size for branch tracing in BTS format.
266 Enable Intel(R) Procesor Trace-based branch tracing for the current
267 process. The remote stub reports support for this packet to GDB's
271 Set the requested ring buffer size for branch tracing in Intel(R) Processor
275 Indicates a memory breakpoint instruction was executed, irrespective
276 of whether it was GDB that planted the breakpoint or the breakpoint
277 is hardcoded in the program. This is required for correct non-stop
281 Indicates the target stopped for a hardware breakpoint. This is
282 required for correct non-stop mode operation.
285 Return information about files on the remote system.
288 Return the full absolute name of the file that was executed to
289 create a process running on the remote system.
292 Select the filesystem on which vFile: operations with filename
293 arguments will operate. This is required for GDB to be able to
294 access files on remote targets where the remote stub does not
295 share a common filesystem with the inferior(s).
298 Indicates that a fork system call was executed.
301 Indicates that a vfork system call was executed.
303 vforkdone stop reason
304 Indicates that a vfork child of the specified process has executed
305 an exec or exit, allowing the vfork parent to resume execution.
307 fork-events and vfork-events features in qSupported
308 The qSupported packet allows GDB to request support for fork and
309 vfork events using new 'gdbfeatures' fork-events and vfork-events,
310 and the qSupported response can contain the corresponding
311 'stubfeatures'. Set and show commands can be used to display
312 whether these features are enabled.
314 * Extended-remote fork events
316 ** GDB now has support for fork events on extended-remote Linux
317 targets. For targets with Linux kernels 2.5.60 and later, this
318 enables follow-fork-mode and detach-on-fork for both fork and
319 vfork, as well as fork and vfork catchpoints.
321 * The info record command now shows the recording format and the
322 branch tracing configuration for the current thread when using
323 the btrace record target.
324 For the BTS format, it shows the ring buffer size.
326 * GDB now has support for DTrace USDT (Userland Static Defined
327 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
329 * GDB now supports access to vector registers on S/390 GNU/Linux
332 * Removed command line options
334 -xdb HP-UX XDB compatibility mode.
336 * Removed targets and native configurations
338 HP/PA running HP-UX hppa*-*-hpux*
339 Itanium running HP-UX ia64-*-hpux*
341 * New configure options
344 This configure option allows the user to build GDB with support for
345 Intel(R) Processor Trace (default: auto). This requires libipt.
347 --with-libipt-prefix=PATH
348 Specify the path to the version of libipt that GDB should use.
349 $PATH/include should contain the intel-pt.h header and
350 $PATH/lib should contain the libipt.so library.
352 *** Changes in GDB 7.9.1
356 ** Xmethods can now specify a result type.
358 *** Changes in GDB 7.9
360 * GDB now supports hardware watchpoints on x86 GNU Hurd.
364 ** You can now access frame registers from Python scripts.
365 ** New attribute 'producer' for gdb.Symtab objects.
366 ** gdb.Objfile objects have a new attribute "progspace",
367 which is the gdb.Progspace object of the containing program space.
368 ** gdb.Objfile objects have a new attribute "owner".
369 ** gdb.Objfile objects have a new attribute "build_id",
370 which is the build ID generated when the file was built.
371 ** gdb.Objfile objects have a new method "add_separate_debug_file".
372 ** A new event "gdb.clear_objfiles" has been added, triggered when
373 selecting a new file to debug.
374 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
375 ** New function gdb.lookup_objfile.
377 New events which are triggered when GDB modifies the state of the
380 ** gdb.events.inferior_call_pre: Function call is about to be made.
381 ** gdb.events.inferior_call_post: Function call has just been made.
382 ** gdb.events.memory_changed: A memory location has been altered.
383 ** gdb.events.register_changed: A register has been altered.
385 * New Python-based convenience functions:
387 ** $_caller_is(name [, number_of_frames])
388 ** $_caller_matches(regexp [, number_of_frames])
389 ** $_any_caller_is(name [, number_of_frames])
390 ** $_any_caller_matches(regexp [, number_of_frames])
392 * GDB now supports the compilation and injection of source code into
393 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
394 to compile the source code to object code, and if successful, inject
395 and execute that code within the current context of the inferior.
396 Currently the C language is supported. The commands used to
397 interface with this new feature are:
399 compile code [-raw|-r] [--] [source code]
400 compile file [-raw|-r] filename
404 demangle [-l language] [--] name
405 Demangle "name" in the specified language, or the current language
406 if elided. This command is renamed from the "maint demangle" command.
407 The latter is kept as a no-op to avoid "maint demangle" being interpreted
408 as "maint demangler-warning".
410 queue-signal signal-name-or-number
411 Queue a signal to be delivered to the thread when it is resumed.
413 add-auto-load-scripts-directory directory
414 Add entries to the list of directories from which to load auto-loaded
417 maint print user-registers
418 List all currently available "user" registers.
420 compile code [-r|-raw] [--] [source code]
421 Compile, inject, and execute in the inferior the executable object
422 code produced by compiling the provided source code.
424 compile file [-r|-raw] filename
425 Compile and inject into the inferior the executable object code
426 produced by compiling the source code stored in the filename
429 * On resume, GDB now always passes the signal the program had stopped
430 for to the thread the signal was sent to, even if the user changed
431 threads before resuming. Previously GDB would often (but not
432 always) deliver the signal to the thread that happens to be current
435 * Conversely, the "signal" command now consistently delivers the
436 requested signal to the current thread. GDB now asks for
437 confirmation if the program had stopped for a signal and the user
438 switched threads meanwhile.
440 * "breakpoint always-inserted" modes "off" and "auto" merged.
442 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
443 won't remove breakpoints from the target until all threads stop,
444 even in non-stop mode. The "auto" mode has been removed, and "off"
445 is now the default mode.
449 set debug symbol-lookup
450 show debug symbol-lookup
451 Control display of debugging info regarding symbol lookup.
455 ** The -list-thread-groups command outputs an exit-code field for
456 inferiors that have exited.
460 MIPS SDE mips*-sde*-elf*
464 Support for these obsolete configurations has been removed.
466 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
467 SGI Irix-5.x mips-*-irix5*
468 SGI Irix-6.x mips-*-irix6*
469 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
470 VAX running Ultrix vax-*-ultrix*
472 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
473 and "assf"), have been removed. Use the "sharedlibrary" command, or
474 its alias "share", instead.
476 *** Changes in GDB 7.8
478 * New command line options
481 This is an alias for the --data-directory option.
483 * GDB supports printing and modifying of variable length automatic arrays
484 as specified in ISO C99.
486 * The ARM simulator now supports instruction level tracing
487 with or without disassembly.
491 GDB now has support for scripting using Guile. Whether this is
492 available is determined at configure time.
493 Guile version 2.0 or greater is required.
494 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
496 * New commands (for set/show, see "New options" below)
500 Invoke CODE by passing it to the Guile interpreter.
504 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
506 info auto-load guile-scripts [regexp]
507 Print the list of automatically loaded Guile scripts.
509 * The source command is now capable of sourcing Guile scripts.
510 This feature is dependent on the debugger being built with Guile support.
514 set print symbol-loading (off|brief|full)
515 show print symbol-loading
516 Control whether to print informational messages when loading symbol
517 information for a file. The default is "full", but when debugging
518 programs with large numbers of shared libraries the amount of output
521 set guile print-stack (none|message|full)
522 show guile print-stack
523 Show a stack trace when an error is encountered in a Guile script.
525 set auto-load guile-scripts (on|off)
526 show auto-load guile-scripts
527 Control auto-loading of Guile script files.
529 maint ada set ignore-descriptive-types (on|off)
530 maint ada show ignore-descriptive-types
531 Control whether the debugger should ignore descriptive types in Ada
532 programs. The default is not to ignore the descriptive types. See
533 the user manual for more details on descriptive types and the intended
534 usage of this option.
536 set auto-connect-native-target
538 Control whether GDB is allowed to automatically connect to the
539 native target for the run, attach, etc. commands when not connected
540 to any target yet. See also "target native" below.
542 set record btrace replay-memory-access (read-only|read-write)
543 show record btrace replay-memory-access
544 Control what memory accesses are allowed during replay.
546 maint set target-async (on|off)
547 maint show target-async
548 This controls whether GDB targets operate in synchronous or
549 asynchronous mode. Normally the default is asynchronous, if it is
550 available; but this can be changed to more easily debug problems
551 occurring only in synchronous mode.
553 set mi-async (on|off)
555 Control whether MI asynchronous mode is preferred. This supersedes
556 "set target-async" of previous GDB versions.
558 * "set target-async" is deprecated as a CLI option and is now an alias
559 for "set mi-async" (only puts MI into async mode).
561 * Background execution commands (e.g., "c&", "s&", etc.) are now
562 possible ``out of the box'' if the target supports them. Previously
563 the user would need to explicitly enable the possibility with the
564 "set target-async on" command.
566 * New features in the GDB remote stub, GDBserver
568 ** New option --debug-format=option1[,option2,...] allows one to add
569 additional text to each output. At present only timestamps
570 are supported: --debug-format=timestamps.
571 Timestamps can also be turned on with the
572 "monitor set debug-format timestamps" command from GDB.
574 * The 'record instruction-history' command now starts counting instructions
575 at one. This also affects the instruction ranges reported by the
576 'record function-call-history' command when given the /i modifier.
578 * The command 'record function-call-history' supports a new modifier '/c' to
579 indent the function names based on their call stack depth.
580 The fields for the '/i' and '/l' modifier have been reordered.
581 The source line range is now prefixed with 'at'.
582 The instruction range is now prefixed with 'inst'.
583 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
584 "record instruction-history" and "list" commands.
586 * The ranges given as arguments to the 'record function-call-history' and
587 'record instruction-history' commands are now inclusive.
589 * The btrace record target now supports the 'record goto' command.
590 For locations inside the execution trace, the back trace is computed
591 based on the information stored in the execution trace.
593 * The btrace record target supports limited reverse execution and replay.
594 The target does not record data and therefore does not allow reading
597 * The "catch syscall" command now works on s390*-linux* targets.
599 * The "compare-sections" command is no longer specific to target
600 remote. It now works with all targets.
602 * All native targets are now consistently called "native".
603 Consequently, the "target child", "target GNU", "target djgpp",
604 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
605 commands have been replaced with "target native". The QNX/NTO port
606 leaves the "procfs" target in place and adds a "native" target for
607 consistency with other ports. The impact on users should be minimal
608 as these commands previously either throwed an error, or were
609 no-ops. The target's name is visible in the output of the following
610 commands: "help target", "info target", "info files", "maint print
613 * The "target native" command now connects to the native target. This
614 can be used to launch native programs even when "set
615 auto-connect-native-target" is set to off.
617 * GDB now supports access to Intel(R) MPX registers on GNU/Linux.
619 * Support for Intel(R) AVX-512 registers on GNU/Linux.
620 Support displaying and modifying Intel(R) AVX-512 registers
621 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
625 qXfer:btrace:read's annex
626 The qXfer:btrace:read packet supports a new annex 'delta' to read
627 branch trace incrementally.
631 ** Valid Python operations on gdb.Value objects representing
632 structs/classes invoke the corresponding overloaded operators if
634 ** New `Xmethods' feature in the Python API. Xmethods are
635 additional methods or replacements for existing methods of a C++
636 class. This feature is useful for those cases where a method
637 defined in C++ source code could be inlined or optimized out by
638 the compiler, making it unavailable to GDB.
641 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
643 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
644 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
645 its alias "share", instead.
647 * The commands "set remotebaud" and "show remotebaud" are no longer
648 supported. Use "set serial baud" and "show serial baud" (respectively)
653 ** A new option "-gdb-set mi-async" replaces "-gdb-set
654 target-async". The latter is left as a deprecated alias of the
655 former for backward compatibility. If the target supports it,
656 CLI background execution commands are now always possible by
657 default, independently of whether the frontend stated a
658 preference for asynchronous execution with "-gdb-set mi-async".
659 Previously "-gdb-set target-async off" affected both MI execution
660 commands and CLI execution commands.
662 *** Changes in GDB 7.7
664 * Improved support for process record-replay and reverse debugging on
665 arm*-linux* targets. Support for thumb32 and syscall instruction
666 recording has been added.
668 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
670 * GDB now supports Fission DWP file format version 2.
671 http://gcc.gnu.org/wiki/DebugFission
673 * New convenience function "$_isvoid", to check whether an expression
674 is void. A void expression is an expression where the type of the
675 result is "void". For example, some convenience variables may be
676 "void" when evaluated (e.g., "$_exitcode" before the execution of
677 the program being debugged; or an undefined convenience variable).
678 Another example, when calling a function whose return type is
681 * The "maintenance print objfiles" command now takes an optional regexp.
683 * The "catch syscall" command now works on arm*-linux* targets.
685 * GDB now consistently shows "<not saved>" when printing values of
686 registers the debug info indicates have not been saved in the frame
687 and there's nowhere to retrieve them from
688 (callee-saved/call-clobbered registers):
693 (gdb) info registers rax
696 Before, the former would print "<optimized out>", and the latter
697 "*value not available*".
699 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
704 ** Frame filters and frame decorators have been added.
705 ** Temporary breakpoints are now supported.
706 ** Line tables representation has been added.
707 ** New attribute 'parent_type' for gdb.Field objects.
708 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
709 ** New attribute 'name' for gdb.Type objects.
713 Nios II ELF nios2*-*-elf
714 Nios II GNU/Linux nios2*-*-linux
715 Texas Instruments MSP430 msp430*-*-elf
717 * Removed native configurations
719 Support for these a.out NetBSD and OpenBSD obsolete configurations has
720 been removed. ELF variants of these configurations are kept supported.
722 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
723 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
724 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
725 i[34567]86-*-openbsd3.[0-3]
726 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
727 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
728 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
732 Like "catch throw", but catches a re-thrown exception.
734 Renamed from old "maint check-symtabs".
736 Perform consistency checks on symtabs.
738 Expand symtabs matching an optional regexp.
741 Display the details of GDB configure-time options.
743 maint set|show per-command
744 maint set|show per-command space
745 maint set|show per-command time
746 maint set|show per-command symtab
747 Enable display of per-command gdb resource usage.
749 remove-symbol-file FILENAME
750 remove-symbol-file -a ADDRESS
751 Remove a symbol file added via add-symbol-file. The file to remove
752 can be identified by its filename or by an address that lies within
753 the boundaries of this symbol file in memory.
756 info exceptions REGEXP
757 Display the list of Ada exceptions defined in the program being
758 debugged. If provided, only the exceptions whose names match REGEXP
763 set debug symfile off|on
765 Control display of debugging info regarding reading symbol files and
766 symbol tables within those files
768 set print raw frame-arguments
769 show print raw frame-arguments
770 Set/show whether to print frame arguments in raw mode,
771 disregarding any defined pretty-printers.
773 set remote trace-status-packet
774 show remote trace-status-packet
775 Set/show the use of remote protocol qTStatus packet.
779 Control display of debugging messages related to Nios II targets.
783 Control whether target-assisted range stepping is enabled.
785 set startup-with-shell
786 show startup-with-shell
787 Specifies whether Unix child processes are started via a shell or
792 Use the target memory cache for accesses to the code segment. This
793 improves performance of remote debugging (particularly disassembly).
795 * You can now use a literal value 'unlimited' for options that
796 interpret 0 or -1 as meaning "unlimited". E.g., "set
797 trace-buffer-size unlimited" is now an alias for "set
798 trace-buffer-size -1" and "set height unlimited" is now an alias for
801 * The "set debug symtab-create" debugging option of GDB has been changed to
802 accept a verbosity level. 0 means "off", 1 provides basic debugging
803 output, and values of 2 or greater provides more verbose output.
805 * New command-line options
807 Display the details of GDB configure-time options.
809 * The command 'tsave' can now support new option '-ctf' to save trace
810 buffer in Common Trace Format.
812 * Newly installed $prefix/bin/gcore acts as a shell interface for the
815 * GDB now implements the the C++ 'typeid' operator.
817 * The new convenience variable $_exception holds the exception being
818 thrown or caught at an exception-related catchpoint.
820 * The exception-related catchpoints, like "catch throw", now accept a
821 regular expression which can be used to filter exceptions by type.
823 * The new convenience variable $_exitsignal is automatically set to
824 the terminating signal number when the program being debugged dies
825 due to an uncaught signal.
829 ** All MI commands now accept an optional "--language" option.
830 Support for this feature can be verified by using the "-list-features"
831 command, which should contain "language-option".
833 ** The new command -info-gdb-mi-command allows the user to determine
834 whether a GDB/MI command is supported or not.
836 ** The "^error" result record returned when trying to execute an undefined
837 GDB/MI command now provides a variable named "code" whose content is the
838 "undefined-command" error code. Support for this feature can be verified
839 by using the "-list-features" command, which should contain
840 "undefined-command-error-code".
842 ** The -trace-save MI command can optionally save trace buffer in Common
845 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
847 ** The command -data-list-register-values now accepts an optional
848 "--skip-unavailable" option. When used, only the available registers
851 ** The new command -trace-frame-collected dumps collected variables,
852 computed expressions, tvars, memory and registers in a traceframe.
854 ** The commands -stack-list-locals, -stack-list-arguments and
855 -stack-list-variables now accept an option "--skip-unavailable".
856 When used, only the available locals or arguments are displayed.
858 ** The -exec-run command now accepts an optional "--start" option.
859 When used, the command follows the same semantics as the "start"
860 command, stopping the program's execution at the start of its
861 main subprogram. Support for this feature can be verified using
862 the "-list-features" command, which should contain
863 "exec-run-start-option".
865 ** The new commands -catch-assert and -catch-exceptions insert
866 catchpoints stopping the program when Ada exceptions are raised.
868 ** The new command -info-ada-exceptions provides the equivalent of
869 the new "info exceptions" command.
871 * New system-wide configuration scripts
872 A GDB installation now provides scripts suitable for use as system-wide
873 configuration scripts for the following systems:
877 * GDB now supports target-assigned range stepping with remote targets.
878 This improves the performance of stepping source lines by reducing
879 the number of control packets from/to GDB. See "New remote packets"
882 * GDB now understands the element 'tvar' in the XML traceframe info.
883 It has the id of the collected trace state variables.
885 * On S/390 targets that provide the transactional-execution feature,
886 the program interruption transaction diagnostic block (TDB) is now
887 represented as a number of additional "registers" in GDB.
893 The vCont packet supports a new 'r' action, that tells the remote
894 stub to step through an address range itself, without GDB
895 involvemement at each single-step.
897 qXfer:libraries-svr4:read's annex
898 The previously unused annex of the qXfer:libraries-svr4:read packet
899 is now used to support passing an argument list. The remote stub
900 reports support for this argument list to GDB's qSupported query.
901 The defined arguments are "start" and "prev", used to reduce work
902 necessary for library list updating, resulting in significant
905 * New features in the GDB remote stub, GDBserver
907 ** GDBserver now supports target-assisted range stepping. Currently
908 enabled on x86/x86_64 GNU/Linux targets.
910 ** GDBserver now adds element 'tvar' in the XML in the reply to
911 'qXfer:traceframe-info:read'. It has the id of the collected
912 trace state variables.
914 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
917 * New 'z' formatter for printing and examining memory, this displays the
918 value as hexadecimal zero padded on the left to the size of the type.
920 * GDB can now use Windows x64 unwinding data.
922 * The "set remotebaud" command has been replaced by "set serial baud".
923 Similarly, "show remotebaud" has been replaced by "show serial baud".
924 The "set remotebaud" and "show remotebaud" commands are still available
925 to provide backward compatibility with older versions of GDB.
927 *** Changes in GDB 7.6
929 * Target record has been renamed to record-full.
930 Record/replay is now enabled with the "record full" command.
931 This also affects settings that are associated with full record/replay
932 that have been moved from "set/show record" to "set/show record full":
934 set|show record full insn-number-max
935 set|show record full stop-at-limit
936 set|show record full memory-query
938 * A new record target "record-btrace" has been added. The new target
939 uses hardware support to record the control-flow of a process. It
940 does not support replaying the execution, but it implements the
941 below new commands for investigating the recorded execution log.
942 This new recording method can be enabled using:
946 The "record-btrace" target is only available on Intel Atom processors
947 and requires a Linux kernel 2.6.32 or later.
949 * Two new commands have been added for record/replay to give information
950 about the recorded execution without having to replay the execution.
951 The commands are only supported by "record btrace".
953 record instruction-history prints the execution history at
954 instruction granularity
956 record function-call-history prints the execution history at
959 * New native configurations
961 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
962 FreeBSD/powerpc powerpc*-*-freebsd
963 x86_64/Cygwin x86_64-*-cygwin*
964 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
968 ARM AArch64 aarch64*-*-elf
969 ARM AArch64 GNU/Linux aarch64*-*-linux
970 Lynx 178 PowerPC powerpc-*-lynx*178
971 x86_64/Cygwin x86_64-*-cygwin*
972 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
974 * If the configured location of system.gdbinit file (as given by the
975 --with-system-gdbinit option at configure time) is in the
976 data-directory (as specified by --with-gdb-datadir at configure
977 time) or in one of its subdirectories, then GDB will look for the
978 system-wide init file in the directory specified by the
979 --data-directory command-line option.
981 * New command line options:
983 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
984 other initialization files, unlike -nx which disables all of them.
986 * Removed command line options
988 -epoch This was used by the gdb mode in Epoch, an ancient fork of
991 * The 'ptype' and 'whatis' commands now accept an argument to control
994 * 'info proc' now works on some core files.
998 ** Vectors can be created with gdb.Type.vector.
1000 ** Python's atexit.register now works in GDB.
1002 ** Types can be pretty-printed via a Python API.
1004 ** Python 3 is now supported (in addition to Python 2.4 or later)
1006 ** New class gdb.Architecture exposes GDB's internal representation
1007 of architecture in the Python API.
1009 ** New method Frame.architecture returns the gdb.Architecture object
1010 corresponding to the frame's architecture.
1012 * New Python-based convenience functions:
1014 ** $_memeq(buf1, buf2, length)
1015 ** $_streq(str1, str2)
1017 ** $_regex(str, regex)
1019 * The 'cd' command now defaults to using '~' (the home directory) if not
1022 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1023 default for GCC since November 2000.
1025 * The command 'forward-search' can now be abbreviated as 'fo'.
1027 * The command 'info tracepoints' can now display 'installed on target'
1028 or 'not installed on target' for each non-pending location of tracepoint.
1030 * New configure options
1032 --enable-libmcheck/--disable-libmcheck
1033 By default, development versions are built with -lmcheck on hosts
1034 that support it, in order to help track memory corruption issues.
1035 Release versions, on the other hand, are built without -lmcheck
1036 by default. The --enable-libmcheck/--disable-libmcheck configure
1037 options allow the user to override that default.
1038 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1039 This configure option allows the user to build GDB with
1040 libbabeltrace using which GDB can read Common Trace Format data.
1042 * New commands (for set/show, see "New options" below)
1045 Catch signals. This is similar to "handle", but allows commands and
1046 conditions to be attached.
1049 List the BFDs known to GDB.
1051 python-interactive [command]
1053 Start a Python interactive prompt, or evaluate the optional command
1054 and print the result of expressions.
1057 "py" is a new alias for "python".
1059 enable type-printer [name]...
1060 disable type-printer [name]...
1061 Enable or disable type printers.
1065 ** For the Renesas Super-H architecture, the "regs" command has been removed
1066 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1071 set print type methods (on|off)
1072 show print type methods
1073 Control whether method declarations are displayed by "ptype".
1074 The default is to show them.
1076 set print type typedefs (on|off)
1077 show print type typedefs
1078 Control whether typedef definitions are displayed by "ptype".
1079 The default is to show them.
1081 set filename-display basename|relative|absolute
1082 show filename-display
1083 Control the way in which filenames is displayed.
1084 The default is "relative", which preserves previous behavior.
1086 set trace-buffer-size
1087 show trace-buffer-size
1088 Request target to change the size of trace buffer.
1090 set remote trace-buffer-size-packet auto|on|off
1091 show remote trace-buffer-size-packet
1092 Control the use of the remote protocol `QTBuffer:size' packet.
1096 Control display of debugging messages related to ARM AArch64.
1099 set debug coff-pe-read
1100 show debug coff-pe-read
1101 Control display of debugging messages related to reading of COFF/PE
1106 Control display of debugging messages related to Mach-O symbols
1109 set debug notification
1110 show debug notification
1111 Control display of debugging info for async remote notification.
1115 ** Command parameter changes are now notified using new async record
1116 "=cmd-param-changed".
1117 ** Trace frame changes caused by command "tfind" are now notified using
1118 new async record "=traceframe-changed".
1119 ** The creation, deletion and modification of trace state variables
1120 are now notified using new async records "=tsv-created",
1121 "=tsv-deleted" and "=tsv-modified".
1122 ** The start and stop of process record are now notified using new
1123 async record "=record-started" and "=record-stopped".
1124 ** Memory changes are now notified using new async record
1126 ** The data-disassemble command response will include a "fullname" field
1127 containing the absolute file name when source has been requested.
1128 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1129 command, to allow pattern filling of memory areas.
1130 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1131 library load/unload events.
1132 ** The response to breakpoint commands and breakpoint async records
1133 includes an "installed" field containing a boolean state about each
1134 non-pending tracepoint location is whether installed on target or not.
1135 ** Output of the "-trace-status" command includes a "trace-file" field
1136 containing the name of the trace file being examined. This field is
1137 optional, and only present when examining a trace file.
1138 ** The "fullname" field is now always present along with the "file" field,
1139 even if the file cannot be found by GDB.
1141 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1142 You must have the LZMA library available when configuring GDB for this
1143 feature to be enabled. For more information, see:
1144 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1146 * New remote packets
1149 Set the size of trace buffer. The remote stub reports support for this
1150 packet to gdb's qSupported query.
1153 Enable Branch Trace Store (BTS)-based branch tracing for the current
1154 thread. The remote stub reports support for this packet to gdb's
1158 Disable branch tracing for the current thread. The remote stub reports
1159 support for this packet to gdb's qSupported query.
1162 Read the traced branches for the current thread. The remote stub
1163 reports support for this packet to gdb's qSupported query.
1165 *** Changes in GDB 7.5
1167 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1168 for more x32 ABI info.
1170 * GDB now supports access to MIPS DSP registers on Linux targets.
1172 * GDB now supports debugging microMIPS binaries.
1174 * The "info os" command on GNU/Linux can now display information on
1175 several new classes of objects managed by the operating system:
1176 "info os procgroups" lists process groups
1177 "info os files" lists file descriptors
1178 "info os sockets" lists internet-domain sockets
1179 "info os shm" lists shared-memory regions
1180 "info os semaphores" lists semaphores
1181 "info os msg" lists message queues
1182 "info os modules" lists loaded kernel modules
1184 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1185 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1186 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1187 options and inspect the probe arguments using the new $_probe_arg family
1188 of convenience variables. You can obtain more information about SystemTap
1189 in <http://sourceware.org/systemtap/>.
1191 * GDB now supports reversible debugging on ARM, it allows you to
1192 debug basic ARM and THUMB instructions, and provides
1193 record/replay support.
1195 * The option "symbol-reloading" has been deleted as it is no longer used.
1199 ** GDB commands implemented in Python can now be put in command class
1202 ** The "maint set python print-stack on|off" is now deleted.
1204 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1205 apply "flag enum"-style pretty-printing to any enum.
1207 ** gdb.lookup_symbol can now work when there is no current frame.
1209 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1210 the source at which the symbol was defined.
1212 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1213 method 'value'. The former indicates whether the symbol needs a
1214 frame in order to compute its value, and the latter computes the
1217 ** A new method 'referenced_value' on gdb.Value objects which can
1218 dereference pointer as well as C++ reference values.
1220 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1221 which return the global and static blocks (as gdb.Block objects),
1222 of the underlying symbol table, respectively.
1224 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1225 object associated with a PC value.
1227 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1228 of the address range occupied by code for the current source line.
1230 * Go language support.
1231 GDB now supports debugging programs written in the Go programming
1234 * GDBserver now supports stdio connections.
1235 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1237 * The binary "gdbtui" can no longer be built or installed.
1238 Use "gdb -tui" instead.
1240 * GDB will now print "flag" enums specially. A flag enum is one where
1241 all the enumerator values have no bits in common when pairwise
1242 "and"ed. When printing a value whose type is a flag enum, GDB will
1243 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1244 (gdb) print (enum E) 3
1247 * The filename part of a linespec will now match trailing components
1248 of a source file name. For example, "break gcc/expr.c:1000" will
1249 now set a breakpoint in build/gcc/expr.c, but not
1250 build/libcpp/expr.c.
1252 * The "info proc" and "generate-core-file" commands will now also
1253 work on remote targets connected to GDBserver on Linux.
1255 * The command "info catch" has been removed. It has been disabled
1256 since December 2007.
1258 * The "catch exception" and "catch assert" commands now accept
1259 a condition at the end of the command, much like the "break"
1260 command does. For instance:
1262 (gdb) catch exception Constraint_Error if Barrier = True
1264 Previously, it was possible to add a condition to such catchpoints,
1265 but it had to be done as a second step, after the catchpoint had been
1266 created, using the "condition" command.
1268 * The "info static-tracepoint-marker" command will now also work on
1269 native Linux targets with in-process agent.
1271 * GDB can now set breakpoints on inlined functions.
1273 * The .gdb_index section has been updated to include symbols for
1274 inlined functions. GDB will ignore older .gdb_index sections by
1275 default, which could cause symbol files to be loaded more slowly
1276 until their .gdb_index sections can be recreated. The new command
1277 "set use-deprecated-index-sections on" will cause GDB to use any older
1278 .gdb_index sections it finds. This will restore performance, but the
1279 ability to set breakpoints on inlined functions will be lost in symbol
1280 files with older .gdb_index sections.
1282 The .gdb_index section has also been updated to record more information
1283 about each symbol. This speeds up the "info variables", "info functions"
1284 and "info types" commands when used with programs having the .gdb_index
1285 section, as well as speeding up debugging with shared libraries using
1286 the .gdb_index section.
1288 * Ada support for GDB/MI Variable Objects has been added.
1290 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1295 ** New command -info-os is the MI equivalent of "info os".
1297 ** Output logs ("set logging" and related) now include MI output.
1301 ** "set use-deprecated-index-sections on|off"
1302 "show use-deprecated-index-sections on|off"
1303 Controls the use of deprecated .gdb_index sections.
1305 ** "catch load" and "catch unload" can be used to stop when a shared
1306 library is loaded or unloaded, respectively.
1308 ** "enable count" can be used to auto-disable a breakpoint after
1311 ** "info vtbl" can be used to show the virtual method tables for
1312 C++ and Java objects.
1314 ** "explore" and its sub commands "explore value" and "explore type"
1315 can be used to recursively explore values and types of
1316 expressions. These commands are available only if GDB is
1317 configured with '--with-python'.
1319 ** "info auto-load" shows status of all kinds of auto-loaded files,
1320 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1321 sequences of commands files, "info auto-load python-scripts"
1322 shows status of auto-loading Python script files,
1323 "info auto-load local-gdbinit" shows status of loading init file
1324 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1325 status of inferior specific thread debugging shared library loading.
1327 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1328 and "show auto-load-scripts" commands have been deprecated, use their
1329 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1330 and "show auto-load python-scripts" counterparts instead.
1332 ** "dprintf location,format,args..." creates a dynamic printf, which
1333 is basically a breakpoint that does a printf and immediately
1334 resumes your program's execution, so it is like a printf that you
1335 can insert dynamically at runtime instead of at compiletime.
1337 ** "set print symbol"
1339 Controls whether GDB attempts to display the symbol, if any,
1340 corresponding to addresses it prints. This defaults to "on", but
1341 you can set it to "off" to restore GDB's previous behavior.
1343 * Deprecated commands
1345 ** For the Renesas Super-H architecture, the "regs" command has been
1346 deprecated, and "info all-registers" should be used instead.
1350 Renesas RL78 rl78-*-elf
1351 HP OpenVMS ia64 ia64-hp-openvms*
1353 * GDBserver supports evaluation of breakpoint conditions. When
1354 support is advertised by GDBserver, GDB may be told to send the
1355 breakpoint conditions in bytecode form to GDBserver. GDBserver
1356 will only report the breakpoint trigger to GDB when its condition
1361 set mips compression
1362 show mips compression
1363 Select the compressed ISA encoding used in functions that have no symbol
1364 information available. The encoding can be set to either of:
1367 and is updated automatically from ELF file flags if available.
1369 set breakpoint condition-evaluation
1370 show breakpoint condition-evaluation
1371 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1372 GDBserver ("target"). Default option "auto" chooses the most efficient
1374 This option can improve debugger efficiency depending on the speed of the
1378 Disable auto-loading globally.
1381 Show auto-loading setting of all kinds of auto-loaded files.
1383 set auto-load gdb-scripts on|off
1384 show auto-load gdb-scripts
1385 Control auto-loading of GDB canned sequences of commands files.
1387 set auto-load python-scripts on|off
1388 show auto-load python-scripts
1389 Control auto-loading of Python script files.
1391 set auto-load local-gdbinit on|off
1392 show auto-load local-gdbinit
1393 Control loading of init file (.gdbinit) from current directory.
1395 set auto-load libthread-db on|off
1396 show auto-load libthread-db
1397 Control auto-loading of inferior specific thread debugging shared library.
1399 set auto-load scripts-directory <dir1>[:<dir2>...]
1400 show auto-load scripts-directory
1401 Set a list of directories from which to load auto-loaded scripts.
1402 Automatically loaded Python scripts and GDB scripts are located in one
1403 of the directories listed by this option.
1404 The delimiter (':' above) may differ according to the host platform.
1406 set auto-load safe-path <dir1>[:<dir2>...]
1407 show auto-load safe-path
1408 Set a list of directories from which it is safe to auto-load files.
1409 The delimiter (':' above) may differ according to the host platform.
1411 set debug auto-load on|off
1412 show debug auto-load
1413 Control display of debugging info for auto-loading the files above.
1415 set dprintf-style gdb|call|agent
1417 Control the way in which a dynamic printf is performed; "gdb"
1418 requests a GDB printf command, while "call" causes dprintf to call a
1419 function in the inferior. "agent" requests that the target agent
1420 (such as GDBserver) do the printing.
1422 set dprintf-function <expr>
1423 show dprintf-function
1424 set dprintf-channel <expr>
1425 show dprintf-channel
1426 Set the function and optional first argument to the call when using
1427 the "call" style of dynamic printf.
1429 set disconnected-dprintf on|off
1430 show disconnected-dprintf
1431 Control whether agent-style dynamic printfs continue to be in effect
1432 after GDB disconnects.
1434 * New configure options
1436 --with-auto-load-dir
1437 Configure default value for the 'set auto-load scripts-directory'
1438 setting above. It defaults to '$debugdir:$datadir/auto-load',
1439 $debugdir representing global debugging info directories (available
1440 via 'show debug-file-directory') and $datadir representing GDB's data
1441 directory (available via 'show data-directory').
1443 --with-auto-load-safe-path
1444 Configure default value for the 'set auto-load safe-path' setting
1445 above. It defaults to the --with-auto-load-dir setting.
1447 --without-auto-load-safe-path
1448 Set 'set auto-load safe-path' to '/', effectively disabling this
1451 * New remote packets
1453 z0/z1 conditional breakpoints extension
1455 The z0/z1 breakpoint insertion packets have been extended to carry
1456 a list of conditional expressions over to the remote stub depending on the
1457 condition evaluation mode. The use of this extension can be controlled
1458 via the "set remote conditional-breakpoints-packet" command.
1462 Specify the signals which the remote stub may pass to the debugged
1463 program without GDB involvement.
1465 * New command line options
1467 --init-command=FILE, -ix Like --command, -x but execute it
1468 before loading inferior.
1469 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
1470 execute it before loading inferior.
1472 *** Changes in GDB 7.4
1474 * GDB now handles ambiguous linespecs more consistently; the existing
1475 FILE:LINE support has been expanded to other types of linespecs. A
1476 breakpoint will now be set on all matching locations in all
1477 inferiors, and locations will be added or removed according to
1480 * GDB now allows you to skip uninteresting functions and files when
1481 stepping with the "skip function" and "skip file" commands.
1483 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
1484 and "show remote hardware-watchpoint-length-limit". These allows to
1485 set or show the maximum length limit (in bytes) of a remote
1486 target hardware watchpoint.
1488 This allows e.g. to use "unlimited" hardware watchpoints with the
1489 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
1490 watchpoints are slower than real hardware watchpoints but are
1491 significantly faster than gdb software watchpoints.
1495 ** The register_pretty_printer function in module gdb.printing now takes
1496 an optional `replace' argument. If True, the new printer replaces any
1499 ** The "maint set python print-stack on|off" command has been
1500 deprecated and will be deleted in GDB 7.5.
1501 A new command: "set python print-stack none|full|message" has
1502 replaced it. Additionally, the default for "print-stack" is
1503 now "message", which just prints the error message without
1506 ** A prompt substitution hook (prompt_hook) is now available to the
1509 ** A new Python module, gdb.prompt has been added to the GDB Python
1510 modules library. This module provides functionality for
1511 escape sequences in prompts (used by set/show
1512 extended-prompt). These escape sequences are replaced by their
1513 corresponding value.
1515 ** Python commands and convenience-functions located in
1516 'data-directory'/python/gdb/command and
1517 'data-directory'/python/gdb/function are now automatically loaded
1520 ** Blocks now provide four new attributes. global_block and
1521 static_block will return the global and static blocks
1522 respectively. is_static and is_global are boolean attributes
1523 that indicate if the block is one of those two types.
1525 ** Symbols now provide the "type" attribute, the type of the symbol.
1527 ** The "gdb.breakpoint" function has been deprecated in favor of
1530 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
1531 of a function. This class is based on the "finish" command
1532 available in the CLI.
1534 ** Type objects for struct and union types now allow access to
1535 the fields using standard Python dictionary (mapping) methods.
1536 For example, "some_type['myfield']" now works, as does
1537 "some_type.items()".
1539 ** A new event "gdb.new_objfile" has been added, triggered by loading a
1542 ** A new function, "deep_items" has been added to the gdb.types
1543 module in the GDB Python modules library. This function returns
1544 an iterator over the fields of a struct or union type. Unlike
1545 the standard Python "iteritems" method, it will recursively traverse
1546 any anonymous fields.
1550 ** "*stopped" events can report several new "reason"s, such as
1553 ** Breakpoint changes are now notified using new async records, like
1554 "=breakpoint-modified".
1556 ** New command -ada-task-info.
1558 * libthread-db-search-path now supports two special values: $sdir and $pdir.
1559 $sdir specifies the default system locations of shared libraries.
1560 $pdir specifies the directory where the libpthread used by the application
1563 GDB no longer looks in $sdir and $pdir after it has searched the directories
1564 mentioned in libthread-db-search-path. If you want to search those
1565 directories, they must be specified in libthread-db-search-path.
1566 The default value of libthread-db-search-path on GNU/Linux and Solaris
1567 systems is now "$sdir:$pdir".
1569 $pdir is not supported by gdbserver, it is currently ignored.
1570 $sdir is supported by gdbserver.
1572 * New configure option --with-iconv-bin.
1573 When using the internationalization support like the one in the GNU C
1574 library, GDB will invoke the "iconv" program to get a list of supported
1575 character sets. If this program lives in a non-standard location, one can
1576 use this option to specify where to find it.
1578 * When natively debugging programs on PowerPC BookE processors running
1579 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
1580 watchpoints, which specify a mask in addition to an address to watch.
1581 The mask specifies that some bits of an address (the bits which are
1582 reset in the mask) should be ignored when matching the address accessed
1583 by the inferior against the watchpoint address. See the "PowerPC Embedded"
1584 section in the user manual for more details.
1586 * The new option --once causes GDBserver to stop listening for connections once
1587 the first connection is made. The listening port used by GDBserver will
1588 become available after that.
1590 * New commands "info macros" and "alias" have been added.
1592 * New function parameters suffix @entry specifies value of function parameter
1593 at the time the function got called. Entry values are available only since
1599 "!" is now an alias of the "shell" command.
1600 Note that no space is needed between "!" and SHELL COMMAND.
1604 watch EXPRESSION mask MASK_VALUE
1605 The watch command now supports the mask argument which allows creation
1606 of masked watchpoints, if the current architecture supports this feature.
1608 info auto-load-scripts [REGEXP]
1609 This command was formerly named "maintenance print section-scripts".
1610 It is now generally useful and is no longer a maintenance-only command.
1612 info macro [-all] [--] MACRO
1613 The info macro command has new options `-all' and `--'. The first for
1614 printing all definitions of a macro. The second for explicitly specifying
1615 the end of arguments and the beginning of the macro name in case the macro
1616 name starts with a hyphen.
1618 collect[/s] EXPRESSIONS
1619 The tracepoint collect command now takes an optional modifier "/s"
1620 that directs it to dereference pointer-to-character types and
1621 collect the bytes of memory up to a zero byte. The behavior is
1622 similar to what you see when you use the regular print command on a
1623 string. An optional integer following the "/s" sets a bound on the
1624 number of bytes that will be collected.
1627 The trace start command now interprets any supplied arguments as a
1628 note to be recorded with the trace run, with an effect similar to
1629 setting the variable trace-notes.
1632 The trace stop command now interprets any arguments as a note to be
1633 mentioned along with the tstatus report that the trace was stopped
1634 with a command. The effect is similar to setting the variable
1637 * Tracepoints can now be enabled and disabled at any time after a trace
1638 experiment has been started using the standard "enable" and "disable"
1639 commands. It is now possible to start a trace experiment with no enabled
1640 tracepoints; GDB will display a warning, but will allow the experiment to
1641 begin, assuming that tracepoints will be enabled as needed while the trace
1644 * Fast tracepoints on 32-bit x86-architectures can now be placed at
1645 locations with 4-byte instructions, when they were previously
1646 limited to locations with instructions of 5 bytes or longer.
1650 set debug dwarf2-read
1651 show debug dwarf2-read
1652 Turns on or off display of debugging messages related to reading
1653 DWARF debug info. The default is off.
1655 set debug symtab-create
1656 show debug symtab-create
1657 Turns on or off display of debugging messages related to symbol table
1658 creation. The default is off.
1661 show extended-prompt
1662 Set the GDB prompt, and allow escape sequences to be inserted to
1663 display miscellaneous information (see 'help set extended-prompt'
1664 for the list of sequences). This prompt (and any information
1665 accessed through the escape sequences) is updated every time the
1666 prompt is displayed.
1668 set print entry-values (both|compact|default|if-needed|no|only|preferred)
1669 show print entry-values
1670 Set printing of frame argument values at function entry. In some cases
1671 GDB can determine the value of function argument which was passed by the
1672 function caller, even if the value was modified inside the called function.
1674 set debug entry-values
1675 show debug entry-values
1676 Control display of debugging info for determining frame argument values at
1677 function entry and virtual tail call frames.
1679 set basenames-may-differ
1680 show basenames-may-differ
1681 Set whether a source file may have multiple base names.
1682 (A "base name" is the name of a file with the directory part removed.
1683 Example: The base name of "/home/user/hello.c" is "hello.c".)
1684 If set, GDB will canonicalize file names (e.g., expand symlinks)
1685 before comparing them. Canonicalization is an expensive operation,
1686 but it allows the same file be known by more than one base name.
1687 If not set (the default), all source files are assumed to have just
1688 one base name, and gdb will do file name comparisons more efficiently.
1694 Set a user name and notes for the current and any future trace runs.
1695 This is useful for long-running and/or disconnected traces, to
1696 inform others (or yourself) as to who is running the trace, supply
1697 contact information, or otherwise explain what is going on.
1699 set trace-stop-notes
1700 show trace-stop-notes
1701 Set a note attached to the trace run, that is displayed when the
1702 trace has been stopped by a tstop command. This is useful for
1703 instance as an explanation, if you are stopping a trace run that was
1704 started by someone else.
1706 * New remote packets
1710 Dynamically enable a tracepoint in a started trace experiment.
1714 Dynamically disable a tracepoint in a started trace experiment.
1718 Set the user and notes of the trace run.
1722 Query the current status of a tracepoint.
1726 Query the minimum length of instruction at which a fast tracepoint may
1729 * Dcache size (number of lines) and line-size are now runtime-configurable
1730 via "set dcache line" and "set dcache line-size" commands.
1734 Texas Instruments TMS320C6x tic6x-*-*
1738 Renesas RL78 rl78-*-elf
1740 *** Changes in GDB 7.3.1
1742 * The build failure for NetBSD and OpenBSD targets have now been fixed.
1744 *** Changes in GDB 7.3
1746 * GDB has a new command: "thread find [REGEXP]".
1747 It finds the thread id whose name, target id, or thread extra info
1748 matches the given regular expression.
1750 * The "catch syscall" command now works on mips*-linux* targets.
1752 * The -data-disassemble MI command now supports modes 2 and 3 for
1753 dumping the instruction opcodes.
1755 * New command line options
1757 -data-directory DIR Specify DIR as the "data-directory".
1758 This is mostly for testing purposes.
1760 * The "maint set python auto-load on|off" command has been renamed to
1761 "set auto-load-scripts on|off".
1763 * GDB has a new command: "set directories".
1764 It is like the "dir" command except that it replaces the
1765 source path list instead of augmenting it.
1767 * GDB now understands thread names.
1769 On GNU/Linux, "info threads" will display the thread name as set by
1770 prctl or pthread_setname_np.
1772 There is also a new command, "thread name", which can be used to
1773 assign a name internally for GDB to display.
1776 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
1777 has been integrated into GDB.
1781 ** The function gdb.Write now accepts an optional keyword 'stream'.
1782 This keyword, when provided, will direct the output to either
1783 stdout, stderr, or GDB's logging output.
1785 ** Parameters can now be be sub-classed in Python, and in particular
1786 you may implement the get_set_doc and get_show_doc functions.
1787 This improves how Parameter set/show documentation is processed
1788 and allows for more dynamic content.
1790 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1791 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1792 have an is_valid method.
1794 ** Breakpoints can now be sub-classed in Python, and in particular
1795 you may implement a 'stop' function that is executed each time
1796 the inferior reaches that breakpoint.
1798 ** New function gdb.lookup_global_symbol looks up a global symbol.
1800 ** GDB values in Python are now callable if the value represents a
1801 function. For example, if 'some_value' represents a function that
1802 takes two integer parameters and returns a value, you can call
1803 that function like so:
1805 result = some_value (10,20)
1807 ** Module gdb.types has been added.
1808 It contains a collection of utilities for working with gdb.Types objects:
1809 get_basic_type, has_field, make_enum_dict.
1811 ** Module gdb.printing has been added.
1812 It contains utilities for writing and registering pretty-printers.
1813 New classes: PrettyPrinter, SubPrettyPrinter,
1814 RegexpCollectionPrettyPrinter.
1815 New function: register_pretty_printer.
1817 ** New commands "info pretty-printers", "enable pretty-printer" and
1818 "disable pretty-printer" have been added.
1820 ** gdb.parameter("directories") is now available.
1822 ** New function gdb.newest_frame returns the newest frame in the
1825 ** The gdb.InferiorThread class has a new "name" attribute. This
1826 holds the thread's name.
1828 ** Python Support for Inferior events.
1829 Python scripts can add observers to be notified of events
1830 occurring in the process being debugged.
1831 The following events are currently supported:
1832 - gdb.events.cont Continue event.
1833 - gdb.events.exited Inferior exited event.
1834 - gdb.events.stop Signal received, and Breakpoint hit events.
1838 ** GDB now puts template parameters in scope when debugging in an
1839 instantiation. For example, if you have:
1841 template<int X> int func (void) { return X; }
1843 then if you step into func<5>, "print X" will show "5". This
1844 feature requires proper debuginfo support from the compiler; it
1845 was added to GCC 4.5.
1847 ** The motion commands "next", "finish", "until", and "advance" now
1848 work better when exceptions are thrown. In particular, GDB will
1849 no longer lose control of the inferior; instead, the GDB will
1850 stop the inferior at the point at which the exception is caught.
1851 This functionality requires a change in the exception handling
1852 code that was introduced in GCC 4.5.
1854 * GDB now follows GCC's rules on accessing volatile objects when
1855 reading or writing target state during expression evaluation.
1856 One notable difference to prior behavior is that "print x = 0"
1857 no longer generates a read of x; the value of the assignment is
1858 now always taken directly from the value being assigned.
1860 * GDB now has some support for using labels in the program's source in
1861 linespecs. For instance, you can use "advance label" to continue
1862 execution to a label.
1864 * GDB now has support for reading and writing a new .gdb_index
1865 section. This section holds a fast index of DWARF debugging
1866 information and can be used to greatly speed up GDB startup and
1867 operation. See the documentation for `save gdb-index' for details.
1869 * The "watch" command now accepts an optional "-location" argument.
1870 When used, this causes GDB to watch the memory referred to by the
1871 expression. Such a watchpoint is never deleted due to it going out
1874 * GDB now supports thread debugging of core dumps on GNU/Linux.
1876 GDB now activates thread debugging using the libthread_db library
1877 when debugging GNU/Linux core dumps, similarly to when debugging
1878 live processes. As a result, when debugging a core dump file, GDB
1879 is now able to display pthread_t ids of threads. For example, "info
1880 threads" shows the same output as when debugging the process when it
1881 was live. In earlier releases, you'd see something like this:
1884 * 1 LWP 6780 main () at main.c:10
1886 While now you see this:
1889 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1891 It is also now possible to inspect TLS variables when debugging core
1894 When debugging a core dump generated on a machine other than the one
1895 used to run GDB, you may need to point GDB at the correct
1896 libthread_db library with the "set libthread-db-search-path"
1897 command. See the user manual for more details on this command.
1899 * When natively debugging programs on PowerPC BookE processors running
1900 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1901 which stop execution of the inferior whenever it executes an instruction
1902 at any address within the specified range. See the "PowerPC Embedded"
1903 section in the user manual for more details.
1905 * New features in the GDB remote stub, GDBserver
1907 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1908 and i686 LynxOS (version 5.x).
1910 ** GDBserver is now supported on Blackfin Linux.
1912 * New native configurations
1914 ia64 HP-UX ia64-*-hpux*
1918 Analog Devices, Inc. Blackfin Processor bfin-*
1920 * Ada task switching is now supported on sparc-elf targets when
1921 debugging a program using the Ravenscar Profile. For more information,
1922 see the "Tasking Support when using the Ravenscar Profile" section
1923 in the GDB user manual.
1925 * Guile support was removed.
1927 * New features in the GNU simulator
1929 ** The --map-info flag lists all known core mappings.
1931 ** CFI flashes may be simulated via the "cfi" device.
1933 *** Changes in GDB 7.2
1935 * Shared library support for remote targets by default
1937 When GDB is configured for a generic, non-OS specific target, like
1938 for example, --target=arm-eabi or one of the many *-*-elf targets,
1939 GDB now queries remote stubs for loaded shared libraries using the
1940 `qXfer:libraries:read' packet. Previously, shared library support
1941 was always disabled for such configurations.
1945 ** Argument Dependent Lookup (ADL)
1947 In C++ ADL lookup directs function search to the namespaces of its
1948 arguments even if the namespace has not been imported.
1958 Here the compiler will search for `foo' in the namespace of 'b'
1959 and find A::foo. GDB now supports this. This construct is commonly
1960 used in the Standard Template Library for operators.
1962 ** Improved User Defined Operator Support
1964 In addition to member operators, GDB now supports lookup of operators
1965 defined in a namespace and imported with a `using' directive, operators
1966 defined in the global scope, operators imported implicitly from an
1967 anonymous namespace, and the ADL operators mentioned in the previous
1969 GDB now also supports proper overload resolution for all the previously
1970 mentioned flavors of operators.
1972 ** static const class members
1974 Printing of static const class members that are initialized in the
1975 class definition has been fixed.
1977 * Windows Thread Information Block access.
1979 On Windows targets, GDB now supports displaying the Windows Thread
1980 Information Block (TIB) structure. This structure is visible either
1981 by using the new command `info w32 thread-information-block' or, by
1982 dereferencing the new convenience variable named `$_tlb', a
1983 thread-specific pointer to the TIB. This feature is also supported
1984 when remote debugging using GDBserver.
1986 * Static tracepoints
1988 Static tracepoints are calls in the user program into a tracing
1989 library. One such library is a port of the LTTng kernel tracer to
1990 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1991 When debugging with GDBserver, GDB now supports combining the GDB
1992 tracepoint machinery with such libraries. For example: the user can
1993 use GDB to probe a static tracepoint marker (a call from the user
1994 program into the tracing library) with the new "strace" command (see
1995 "New commands" below). This creates a "static tracepoint" in the
1996 breakpoint list, that can be manipulated with the same feature set
1997 as fast and regular tracepoints. E.g., collect registers, local and
1998 global variables, collect trace state variables, and define
1999 tracepoint conditions. In addition, the user can collect extra
2000 static tracepoint marker specific data, by collecting the new
2001 $_sdata internal variable. When analyzing the trace buffer, you can
2002 inspect $_sdata like any other variable available to GDB. For more
2003 information, see the "Tracepoints" chapter in GDB user manual. New
2004 remote packets have been defined to support static tracepoints, see
2005 the "New remote packets" section below.
2007 * Better reconstruction of tracepoints after disconnected tracing
2009 GDB will attempt to download the original source form of tracepoint
2010 definitions when starting a trace run, and then will upload these
2011 upon reconnection to the target, resulting in a more accurate
2012 reconstruction of the tracepoints that are in use on the target.
2016 You can now exercise direct control over the ways that GDB can
2017 affect your program. For instance, you can disallow the setting of
2018 breakpoints, so that the program can run continuously (assuming
2019 non-stop mode). In addition, the "observer" variable is available
2020 to switch all of the different controls; in observer mode, GDB
2021 cannot affect the target's behavior at all, which is useful for
2022 tasks like diagnosing live systems in the field.
2024 * The new convenience variable $_thread holds the number of the
2027 * New remote packets
2031 Return the address of the Windows Thread Information Block of a given thread.
2035 In response to several of the tracepoint packets, the target may now
2036 also respond with a number of intermediate `qRelocInsn' request
2037 packets before the final result packet, to have GDB handle
2038 relocating an instruction to execute at a different address. This
2039 is particularly useful for stubs that support fast tracepoints. GDB
2040 reports support for this feature in the qSupported packet.
2044 List static tracepoint markers in the target program.
2048 List static tracepoint markers at a given address in the target
2051 qXfer:statictrace:read
2053 Read the static trace data collected (by a `collect $_sdata'
2054 tracepoint action). The remote stub reports support for this packet
2055 to gdb's qSupported query.
2059 Send the current settings of GDB's permission flags.
2063 Send part of the source (textual) form of a tracepoint definition,
2064 which includes location, conditional, and action list.
2066 * The source command now accepts a -s option to force searching for the
2067 script in the source search path even if the script name specifies
2070 * New features in the GDB remote stub, GDBserver
2072 - GDBserver now support tracepoints (including fast tracepoints, and
2073 static tracepoints). The feature is currently supported by the
2074 i386-linux and amd64-linux builds. See the "Tracepoints support
2075 in gdbserver" section in the manual for more information.
2077 GDBserver JIT compiles the tracepoint's conditional agent
2078 expression bytecode into native code whenever possible for low
2079 overhead dynamic tracepoints conditionals. For such tracepoints,
2080 an expression that examines program state is evaluated when the
2081 tracepoint is reached, in order to determine whether to capture
2082 trace data. If the condition is simple and false, processing the
2083 tracepoint finishes very quickly and no data is gathered.
2085 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2086 for static tracepoints support.
2088 - GDBserver now supports x86_64 Windows 64-bit debugging.
2090 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2091 it understands register description.
2093 * The --batch flag now disables pagination and queries.
2095 * X86 general purpose registers
2097 GDB now supports reading/writing byte, word and double-word x86
2098 general purpose registers directly. This means you can use, say,
2099 $ah or $ax to refer, respectively, to the byte register AH and
2100 16-bit word register AX that are actually portions of the 32-bit
2101 register EAX or 64-bit register RAX.
2103 * The `commands' command now accepts a range of breakpoints to modify.
2104 A plain `commands' following a command that creates multiple
2105 breakpoints affects all the breakpoints set by that command. This
2106 applies to breakpoints set by `rbreak', and also applies when a
2107 single `break' command creates multiple breakpoints (e.g.,
2108 breakpoints on overloaded c++ functions).
2110 * The `rbreak' command now accepts a filename specification as part of
2111 its argument, limiting the functions selected by the regex to those
2112 in the specified file.
2114 * Support for remote debugging Windows and SymbianOS shared libraries
2115 from Unix hosts has been improved. Non Windows GDB builds now can
2116 understand target reported file names that follow MS-DOS based file
2117 system semantics, such as file names that include drive letters and
2118 use the backslash character as directory separator. This makes it
2119 possible to transparently use the "set sysroot" and "set
2120 solib-search-path" on Unix hosts to point as host copies of the
2121 target's shared libraries. See the new command "set
2122 target-file-system-kind" described below, and the "Commands to
2123 specify files" section in the user manual for more information.
2127 eval template, expressions...
2128 Convert the values of one or more expressions under the control
2129 of the string template to a command line, and call it.
2131 set target-file-system-kind unix|dos-based|auto
2132 show target-file-system-kind
2133 Set or show the assumed file system kind for target reported file
2136 save breakpoints <filename>
2137 Save all current breakpoint definitions to a file suitable for use
2138 in a later debugging session. To read the saved breakpoint
2139 definitions, use the `source' command.
2141 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2144 info static-tracepoint-markers
2145 Display information about static tracepoint markers in the target.
2147 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2148 Define a static tracepoint by probing a marker at the given
2149 function, line, address, or marker ID.
2153 Enable and disable observer mode.
2155 set may-write-registers on|off
2156 set may-write-memory on|off
2157 set may-insert-breakpoints on|off
2158 set may-insert-tracepoints on|off
2159 set may-insert-fast-tracepoints on|off
2160 set may-interrupt on|off
2161 Set individual permissions for GDB effects on the target. Note that
2162 some of these settings can have undesirable or surprising
2163 consequences, particularly when changed in the middle of a session.
2164 For instance, disabling the writing of memory can prevent
2165 breakpoints from being inserted, cause single-stepping to fail, or
2166 even crash your program, if you disable after breakpoints have been
2167 inserted. However, GDB should not crash.
2169 set record memory-query on|off
2170 show record memory-query
2171 Control whether to stop the inferior if memory changes caused
2172 by an instruction cannot be recorded.
2177 The disassemble command now supports "start,+length" form of two arguments.
2181 ** GDB now provides a new directory location, called the python directory,
2182 where Python scripts written for GDB can be installed. The location
2183 of that directory is <data-directory>/python, where <data-directory>
2184 is the GDB data directory. For more details, see section `Scripting
2185 GDB using Python' in the manual.
2187 ** The GDB Python API now has access to breakpoints, symbols, symbol
2188 tables, program spaces, inferiors, threads and frame's code blocks.
2189 Additionally, GDB Parameters can now be created from the API, and
2190 manipulated via set/show in the CLI.
2192 ** New functions gdb.target_charset, gdb.target_wide_charset,
2193 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2195 ** New exception gdb.GdbError.
2197 ** Pretty-printers are now also looked up in the current program space.
2199 ** Pretty-printers can now be individually enabled and disabled.
2201 ** GDB now looks for names of Python scripts to auto-load in a
2202 special section named `.debug_gdb_scripts', in addition to looking
2203 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2205 * Tracepoint actions were unified with breakpoint commands. In particular,
2206 there are no longer differences in "info break" output for breakpoints and
2207 tracepoints and the "commands" command can be used for both tracepoints and
2208 regular breakpoints.
2212 ARM Symbian arm*-*-symbianelf*
2214 * D language support.
2215 GDB now supports debugging programs written in the D programming
2218 * GDB now supports the extended ptrace interface for PowerPC which is
2219 available since Linux kernel version 2.6.34. This automatically enables
2220 any hardware breakpoints and additional hardware watchpoints available in
2221 the processor. The old ptrace interface exposes just one hardware
2222 watchpoint and no hardware breakpoints.
2224 * GDB is now able to use the Data Value Compare (DVC) register available on
2225 embedded PowerPC processors to implement in hardware simple watchpoint
2226 conditions of the form:
2228 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2230 This works in native GDB running on Linux kernels with the extended ptrace
2231 interface mentioned above.
2233 *** Changes in GDB 7.1
2237 ** Namespace Support
2239 GDB now supports importing of namespaces in C++. This enables the
2240 user to inspect variables from imported namespaces. Support for
2241 namepace aliasing has also been added. So, if a namespace is
2242 aliased in the current scope (e.g. namepace C=A; ) the user can
2243 print variables using the alias (e.g. (gdb) print C::x).
2247 All known bugs relating to the printing of virtual base class were
2248 fixed. It is now possible to call overloaded static methods using a
2253 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2254 and reinterpret_cast<> are now handled by the C++ expression parser.
2258 Xilinx MicroBlaze microblaze-*-*
2263 Xilinx MicroBlaze microblaze
2266 * Multi-program debugging.
2268 GDB now has support for multi-program (a.k.a. multi-executable or
2269 multi-exec) debugging. This allows for debugging multiple inferiors
2270 simultaneously each running a different program under the same GDB
2271 session. See "Debugging Multiple Inferiors and Programs" in the
2272 manual for more information. This implied some user visible changes
2273 in the multi-inferior support. For example, "info inferiors" now
2274 lists inferiors that are not running yet or that have exited
2275 already. See also "New commands" and "New options" below.
2277 * New tracing features
2279 GDB's tracepoint facility now includes several new features:
2281 ** Trace state variables
2283 GDB tracepoints now include support for trace state variables, which
2284 are variables managed by the target agent during a tracing
2285 experiment. They are useful for tracepoints that trigger each
2286 other, so for instance one tracepoint can count hits in a variable,
2287 and then a second tracepoint has a condition that is true when the
2288 count reaches a particular value. Trace state variables share the
2289 $-syntax of GDB convenience variables, and can appear in both
2290 tracepoint actions and condition expressions. Use the "tvariable"
2291 command to create, and "info tvariables" to view; see "Trace State
2292 Variables" in the manual for more detail.
2296 GDB now includes an option for defining fast tracepoints, which
2297 targets may implement more efficiently, such as by installing a jump
2298 into the target agent rather than a trap instruction. The resulting
2299 speedup can be by two orders of magnitude or more, although the
2300 tradeoff is that some program locations on some target architectures
2301 might not allow fast tracepoint installation, for instance if the
2302 instruction to be replaced is shorter than the jump. To request a
2303 fast tracepoint, use the "ftrace" command, with syntax identical to
2304 the regular trace command.
2306 ** Disconnected tracing
2308 It is now possible to detach GDB from the target while it is running
2309 a trace experiment, then reconnect later to see how the experiment
2310 is going. In addition, a new variable disconnected-tracing lets you
2311 tell the target agent whether to continue running a trace if the
2312 connection is lost unexpectedly.
2316 GDB now has the ability to save the trace buffer into a file, and
2317 then use that file as a target, similarly to you can do with
2318 corefiles. You can select trace frames, print data that was
2319 collected in them, and use tstatus to display the state of the
2320 tracing run at the moment that it was saved. To create a trace
2321 file, use "tsave <filename>", and to use it, do "target tfile
2324 ** Circular trace buffer
2326 You can ask the target agent to handle the trace buffer as a
2327 circular buffer, discarding the oldest trace frames to make room for
2328 newer ones, by setting circular-trace-buffer to on. This feature may
2329 not be available for all target agents.
2334 The disassemble command, when invoked with two arguments, now requires
2335 the arguments to be comma-separated.
2338 The info variables command now displays variable definitions. Files
2339 which only declare a variable are not shown.
2342 The source command is now capable of sourcing Python scripts.
2343 This feature is dependent on the debugger being build with Python
2346 Related to this enhancement is also the introduction of a new command
2347 "set script-extension" (see below).
2349 * New commands (for set/show, see "New options" below)
2351 record save [<FILENAME>]
2352 Save a file (in core file format) containing the process record
2353 execution log for replay debugging at a later time.
2355 record restore <FILENAME>
2356 Restore the process record execution log that was saved at an
2357 earlier time, for replay debugging.
2359 add-inferior [-copies <N>] [-exec <FILENAME>]
2362 clone-inferior [-copies <N>] [ID]
2363 Make a new inferior ready to execute the same program another
2364 inferior has loaded.
2369 maint info program-spaces
2370 List the program spaces loaded into GDB.
2372 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2373 show remote interrupt-sequence
2374 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2375 as the sequence to the remote target in order to interrupt the execution.
2376 Ctrl-C is a default. Some system prefers BREAK which is high level of
2377 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2378 Magic SysRq g. It is BREAK signal and character 'g'.
2380 set remote interrupt-on-connect [on | off]
2381 show remote interrupt-on-connect
2382 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2383 remote target when gdb connects to it. This is needed when you debug
2386 set remotebreak [on | off]
2388 Deprecated. Use "set/show remote interrupt-sequence" instead.
2390 tvariable $NAME [ = EXP ]
2391 Create or modify a trace state variable.
2394 List trace state variables and their values.
2396 delete tvariable $NAME ...
2397 Delete one or more trace state variables.
2400 Evaluate the given expressions without collecting anything into the
2401 trace buffer. (Valid in tracepoint actions only.)
2403 ftrace FN / FILE:LINE / *ADDR
2404 Define a fast tracepoint at the given function, line, or address.
2406 * New expression syntax
2408 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2409 GDB now parses 0b101010 identically with 42.
2413 set follow-exec-mode new|same
2414 show follow-exec-mode
2415 Control whether GDB reuses the same inferior across an exec call or
2416 creates a new one. This is useful to be able to restart the old
2417 executable after the inferior having done an exec call.
2419 set default-collect EXPR, ...
2420 show default-collect
2421 Define a list of expressions to be collected at each tracepoint.
2422 This is a useful way to ensure essential items are not overlooked,
2423 such as registers or a critical global variable.
2425 set disconnected-tracing
2426 show disconnected-tracing
2427 If set to 1, the target is instructed to continue tracing if it
2428 loses its connection to GDB. If 0, the target is to stop tracing
2431 set circular-trace-buffer
2432 show circular-trace-buffer
2433 If set to on, the target is instructed to use a circular trace buffer
2434 and discard the oldest trace frames instead of stopping the trace due
2435 to a full trace buffer. If set to off, the trace stops when the buffer
2436 fills up. Some targets may not support this.
2438 set script-extension off|soft|strict
2439 show script-extension
2440 If set to "off", the debugger does not perform any script language
2441 recognition, and all sourced files are assumed to be GDB scripts.
2442 If set to "soft" (the default), files are sourced according to
2443 filename extension, falling back to GDB scripts if the first
2445 If set to "strict", files are sourced according to filename extension.
2447 set ada trust-PAD-over-XVS on|off
2448 show ada trust-PAD-over-XVS
2449 If off, activate a workaround against a bug in the debugging information
2450 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
2451 the GCC sources for more information about the GNAT encoding and
2452 PAD types in particular). It is always safe to set this option to
2453 off, but this introduces a slight performance penalty. The default
2456 * Python API Improvements
2458 ** GDB provides the new class gdb.LazyString. This is useful in
2459 some pretty-printing cases. The new method gdb.Value.lazy_string
2460 provides a simple way to create objects of this type.
2462 ** The fields returned by gdb.Type.fields now have an
2463 `is_base_class' attribute.
2465 ** The new method gdb.Type.range returns the range of an array type.
2467 ** The new method gdb.parse_and_eval can be used to parse and
2468 evaluate an expression.
2470 * New remote packets
2473 Define a trace state variable.
2476 Get the current value of a trace state variable.
2479 Set desired tracing behavior upon disconnection.
2482 Set the trace buffer to be linear or circular.
2485 Get data about the tracepoints currently in use.
2489 Process record now works correctly with hardware watchpoints.
2491 Multiple bug fixes have been made to the mips-irix port, making it
2492 much more reliable. In particular:
2493 - Debugging threaded applications is now possible again. Previously,
2494 GDB would hang while starting the program, or while waiting for
2495 the program to stop at a breakpoint.
2496 - Attaching to a running process no longer hangs.
2497 - An error occurring while loading a core file has been fixed.
2498 - Changing the value of the PC register now works again. This fixes
2499 problems observed when using the "jump" command, or when calling
2500 a function from GDB, or even when assigning a new value to $pc.
2501 - With the "finish" and "return" commands, the return value for functions
2502 returning a small array is now correctly printed.
2503 - It is now possible to break on shared library code which gets executed
2504 during a shared library init phase (code executed while executing
2505 their .init section). Previously, the breakpoint would have no effect.
2506 - GDB is now able to backtrace through the signal handler for
2507 non-threaded programs.
2509 PIE (Position Independent Executable) programs debugging is now supported.
2510 This includes debugging execution of PIC (Position Independent Code) shared
2511 libraries although for that, it should be possible to run such libraries as an
2514 *** Changes in GDB 7.0
2516 * GDB now has an interface for JIT compilation. Applications that
2517 dynamically generate code can create symbol files in memory and register
2518 them with GDB. For users, the feature should work transparently, and
2519 for JIT developers, the interface is documented in the GDB manual in the
2520 "JIT Compilation Interface" chapter.
2522 * Tracepoints may now be conditional. The syntax is as for
2523 breakpoints; either an "if" clause appended to the "trace" command,
2524 or the "condition" command is available. GDB sends the condition to
2525 the target for evaluation using the same bytecode format as is used
2526 for tracepoint actions.
2528 * The disassemble command now supports: an optional /r modifier, print the
2529 raw instructions in hex as well as in symbolic form, and an optional /m
2530 modifier to print mixed source+assembly.
2532 * Process record and replay
2534 In a architecture environment that supports ``process record and
2535 replay'', ``process record and replay'' target can record a log of
2536 the process execution, and replay it with both forward and reverse
2539 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
2540 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
2541 set execution-direction {forward|reverse}, for targets that support
2544 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
2545 feature is available with a native GDB running on kernel version
2548 * GDB now has support for multi-byte and wide character sets on the
2549 target. Strings whose character type is wchar_t, char16_t, or
2550 char32_t are now correctly printed. GDB supports wide- and unicode-
2551 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
2552 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
2553 `printf'. This feature requires iconv to work properly; if your
2554 system does not have a working iconv, GDB can use GNU libiconv. See
2555 the installation instructions for more information.
2557 * GDB now supports automatic retrieval of shared library files from
2558 remote targets. To use this feature, specify a system root that begins
2559 with the `remote:' prefix, either via the `set sysroot' command or via
2560 the `--with-sysroot' configure-time option.
2562 * "info sharedlibrary" now takes an optional regex of libraries to show,
2563 and it now reports if a shared library has no debugging information.
2565 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
2566 now complete on file names.
2568 * When completing in expressions, gdb will attempt to limit
2569 completions to allowable structure or union fields, where appropriate.
2570 For instance, consider:
2572 # struct example { int f1; double f2; };
2573 # struct example variable;
2576 If the user types TAB at the end of this command line, the available
2577 completions will be "f1" and "f2".
2579 * Inlined functions are now supported. They show up in backtraces, and
2580 the "step", "next", and "finish" commands handle them automatically.
2582 * GDB now supports the token-splicing (##) and stringification (#)
2583 operators when expanding macros. It also supports variable-arity
2586 * GDB now supports inspecting extra signal information, exported by
2587 the new $_siginfo convenience variable. The feature is currently
2588 implemented on linux ARM, i386 and amd64.
2590 * GDB can now display the VFP floating point registers and NEON vector
2591 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
2592 can provide these registers (requires Linux 2.6.30 or later). Remote
2593 and simulator targets may also provide them.
2595 * New remote packets
2598 Search memory for a sequence of bytes.
2601 Turn off `+'/`-' protocol acknowledgments to permit more efficient
2602 operation over reliable transport links. Use of this packet is
2603 controlled by the `set remote noack-packet' command.
2606 Kill the process with the specified process ID. Use this in preference
2607 to `k' when multiprocess protocol extensions are supported.
2610 Obtains additional operating system information
2614 Read or write additional signal information.
2616 * Removed remote protocol undocumented extension
2618 An undocumented extension to the remote protocol's `S' stop reply
2619 packet that permited the stub to pass a process id was removed.
2620 Remote servers should use the `T' stop reply packet instead.
2622 * GDB now supports multiple function calling conventions according to the
2623 DWARF-2 DW_AT_calling_convention function attribute.
2625 * The SH target utilizes the aforementioned change to distinguish between gcc
2626 and Renesas calling convention. It also adds the new CLI commands
2627 `set/show sh calling-convention'.
2629 * GDB can now read compressed debug sections, as produced by GNU gold
2630 with the --compress-debug-sections=zlib flag.
2632 * 64-bit core files are now supported on AIX.
2634 * Thread switching is now supported on Tru64.
2636 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
2637 which will be allocated using malloc later in program execution.
2639 * The qXfer:libraries:read remote procotol packet now allows passing a
2640 list of section offsets.
2642 * On GNU/Linux, GDB can now attach to stopped processes. Several race
2643 conditions handling signals delivered during attach or thread creation
2644 have also been fixed.
2646 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
2647 From the user's standpoint, all unqualified instances of True and False
2648 are treated as the standard definitions, regardless of context.
2650 * GDB now parses C++ symbol and type names more flexibly. For
2653 template<typename T> class C { };
2656 GDB will now correctly handle all of:
2658 ptype C<char const *>
2659 ptype C<char const*>
2660 ptype C<const char *>
2661 ptype C<const char*>
2663 * New features in the GDB remote stub, gdbserver
2665 - The "--wrapper" command-line argument tells gdbserver to use a
2666 wrapper program to launch programs for debugging.
2668 - On PowerPC and S/390 targets, it is now possible to use a single
2669 gdbserver executable to debug both 32-bit and 64-bit programs.
2670 (This requires gdbserver itself to be built as a 64-bit executable.)
2672 - gdbserver uses the new noack protocol mode for TCP connections to
2673 reduce communications latency, if also supported and enabled in GDB.
2675 - Support for the sparc64-linux-gnu target is now included in
2678 - The amd64-linux build of gdbserver now supports debugging both
2679 32-bit and 64-bit programs.
2681 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
2682 now support hardware watchpoints, and will use them automatically
2687 GDB now has support for scripting using Python. Whether this is
2688 available is determined at configure time.
2690 New GDB commands can now be written in Python.
2692 * Ada tasking support
2694 Ada tasks can now be inspected in GDB. The following commands have
2698 Print the list of Ada tasks.
2700 Print detailed information about task number N.
2702 Print the task number of the current task.
2704 Switch the context of debugging to task number N.
2706 * Support for user-defined prefixed commands. The "define" command can
2707 add new commands to existing prefixes, e.g. "target".
2709 * Multi-inferior, multi-process debugging.
2711 GDB now has generalized support for multi-inferior debugging. See
2712 "Debugging Multiple Inferiors" in the manual for more information.
2713 Although availability still depends on target support, the command
2714 set is more uniform now. The GNU/Linux specific multi-forks support
2715 has been migrated to this new framework. This implied some user
2716 visible changes; see "New commands" and also "Removed commands"
2719 * Target descriptions can now describe the target OS ABI. See the
2720 "Target Description Format" section in the user manual for more
2723 * Target descriptions can now describe "compatible" architectures
2724 to indicate that the target can execute applications for a different
2725 architecture in addition to those for the main target architecture.
2726 See the "Target Description Format" section in the user manual for
2729 * Multi-architecture debugging.
2731 GDB now includes general supports for debugging applications on
2732 hybrid systems that use more than one single processor architecture
2733 at the same time. Each such hybrid architecture still requires
2734 specific support to be added. The only hybrid architecture supported
2735 in this version of GDB is the Cell Broadband Engine.
2737 * GDB now supports integrated debugging of Cell/B.E. applications that
2738 use both the PPU and SPU architectures. To enable support for hybrid
2739 Cell/B.E. debugging, you need to configure GDB to support both the
2740 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
2741 --enable-targets configure option.
2743 * Non-stop mode debugging.
2745 For some targets, GDB now supports an optional mode of operation in
2746 which you can examine stopped threads while other threads continue
2747 to execute freely. This is referred to as non-stop mode, with the
2748 old mode referred to as all-stop mode. See the "Non-Stop Mode"
2749 section in the user manual for more information.
2751 To be able to support remote non-stop debugging, a remote stub needs
2752 to implement the non-stop mode remote protocol extensions, as
2753 described in the "Remote Non-Stop" section of the user manual. The
2754 GDB remote stub, gdbserver, has been adjusted to support these
2755 extensions on linux targets.
2757 * New commands (for set/show, see "New options" below)
2759 catch syscall [NAME(S) | NUMBER(S)]
2760 Catch system calls. Arguments, which should be names of system
2761 calls or their numbers, mean catch only those syscalls. Without
2762 arguments, every syscall will be caught. When the inferior issues
2763 any of the specified syscalls, GDB will stop and announce the system
2764 call, both when it is called and when its call returns. This
2765 feature is currently available with a native GDB running on the
2766 Linux Kernel, under the following architectures: x86, x86_64,
2767 PowerPC and PowerPC64.
2769 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
2771 Search memory for a sequence of bytes.
2773 maint set python print-stack
2774 maint show python print-stack
2775 Show a stack trace when an error is encountered in a Python script.
2778 Invoke CODE by passing it to the Python interpreter.
2783 These allow macros to be defined, undefined, and listed
2787 Show operating system information about processes.
2790 List the inferiors currently under GDB's control.
2793 Switch focus to inferior number NUM.
2796 Detach from inferior number NUM.
2799 Kill inferior number NUM.
2803 set spu stop-on-load
2804 show spu stop-on-load
2805 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2807 set spu auto-flush-cache
2808 show spu auto-flush-cache
2809 Control whether to automatically flush the software-managed cache
2810 during Cell/B.E. debugging.
2812 set sh calling-convention
2813 show sh calling-convention
2814 Control the calling convention used when calling SH target functions.
2817 show debug timestamp
2818 Control display of timestamps with GDB debugging output.
2820 set disassemble-next-line
2821 show disassemble-next-line
2822 Control display of disassembled source lines or instructions when
2825 set remote noack-packet
2826 show remote noack-packet
2827 Set/show the use of remote protocol QStartNoAckMode packet. See above
2828 under "New remote packets."
2830 set remote query-attached-packet
2831 show remote query-attached-packet
2832 Control use of remote protocol `qAttached' (query-attached) packet.
2834 set remote read-siginfo-object
2835 show remote read-siginfo-object
2836 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2839 set remote write-siginfo-object
2840 show remote write-siginfo-object
2841 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2844 set remote reverse-continue
2845 show remote reverse-continue
2846 Control use of remote protocol 'bc' (reverse-continue) packet.
2848 set remote reverse-step
2849 show remote reverse-step
2850 Control use of remote protocol 'bs' (reverse-step) packet.
2852 set displaced-stepping
2853 show displaced-stepping
2854 Control displaced stepping mode. Displaced stepping is a way to
2855 single-step over breakpoints without removing them from the debuggee.
2856 Also known as "out-of-line single-stepping".
2859 show debug displaced
2860 Control display of debugging info for displaced stepping.
2862 maint set internal-error
2863 maint show internal-error
2864 Control what GDB does when an internal error is detected.
2866 maint set internal-warning
2867 maint show internal-warning
2868 Control what GDB does when an internal warning is detected.
2873 Use a wrapper program to launch programs for debugging.
2875 set multiple-symbols (all|ask|cancel)
2876 show multiple-symbols
2877 The value of this variable can be changed to adjust the debugger behavior
2878 when an expression or a breakpoint location contains an ambiguous symbol
2879 name (an overloaded function name, for instance).
2881 set breakpoint always-inserted
2882 show breakpoint always-inserted
2883 Keep breakpoints always inserted in the target, as opposed to inserting
2884 them when resuming the target, and removing them when the target stops.
2885 This option can improve debugger performance on slow remote targets.
2887 set arm fallback-mode (arm|thumb|auto)
2888 show arm fallback-mode
2889 set arm force-mode (arm|thumb|auto)
2891 These commands control how ARM GDB determines whether instructions
2892 are ARM or Thumb. The default for both settings is auto, which uses
2893 the current CPSR value for instructions without symbols; previous
2894 versions of GDB behaved as if "set arm fallback-mode arm".
2896 set disable-randomization
2897 show disable-randomization
2898 Standalone programs run with the virtual address space randomization enabled
2899 by default on some platforms. This option keeps the addresses stable across
2900 multiple debugging sessions.
2904 Control whether other threads are stopped or not when some thread hits
2909 Requests that asynchronous execution is enabled in the target, if available.
2910 In this case, it's possible to resume target in the background, and interact
2911 with GDB while the target is running. "show target-async" displays the
2912 current state of asynchronous execution of the target.
2914 set target-wide-charset
2915 show target-wide-charset
2916 The target-wide-charset is the name of the character set that GDB
2917 uses when printing characters whose type is wchar_t.
2919 set tcp auto-retry (on|off)
2921 set tcp connect-timeout
2922 show tcp connect-timeout
2923 These commands allow GDB to retry failed TCP connections to a remote stub
2924 with a specified timeout period; this is useful if the stub is launched
2925 in parallel with GDB but may not be ready to accept connections immediately.
2927 set libthread-db-search-path
2928 show libthread-db-search-path
2929 Control list of directories which GDB will search for appropriate
2932 set schedule-multiple (on|off)
2933 show schedule-multiple
2934 Allow GDB to resume all threads of all processes or only threads of
2935 the current process.
2939 Use more aggressive caching for accesses to the stack. This improves
2940 performance of remote debugging (particularly backtraces) without
2941 affecting correctness.
2943 set interactive-mode (on|off|auto)
2944 show interactive-mode
2945 Control whether GDB runs in interactive mode (on) or not (off).
2946 When in interactive mode, GDB waits for the user to answer all
2947 queries. Otherwise, GDB does not wait and assumes the default
2948 answer. When set to auto (the default), GDB determines which
2949 mode to use based on the stdin settings.
2954 For program forks, this is replaced by the new more generic `info
2955 inferiors' command. To list checkpoints, you can still use the
2956 `info checkpoints' command, which was an alias for the `info forks'
2960 Replaced by the new `inferior' command. To switch between
2961 checkpoints, you can still use the `restart' command, which was an
2962 alias for the `fork' command.
2965 This is removed, since some targets don't have a notion of
2966 processes. To switch between processes, you can still use the
2967 `inferior' command using GDB's own inferior number.
2970 For program forks, this is replaced by the new more generic `kill
2971 inferior' command. To delete a checkpoint, you can still use the
2972 `delete checkpoint' command, which was an alias for the `delete
2976 For program forks, this is replaced by the new more generic `detach
2977 inferior' command. To detach a checkpoint, you can still use the
2978 `detach checkpoint' command, which was an alias for the `detach
2981 * New native configurations
2983 x86/x86_64 Darwin i[34567]86-*-darwin*
2985 x86_64 MinGW x86_64-*-mingw*
2989 Lattice Mico32 lm32-*
2990 x86 DICOS i[34567]86-*-dicos*
2991 x86_64 DICOS x86_64-*-dicos*
2994 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2995 (mingw32ce) debugging.
3001 These commands were actually not implemented on any target.
3003 *** Changes in GDB 6.8
3005 * New native configurations
3007 NetBSD/hppa hppa*-*netbsd*
3008 Xtensa GNU/Linux xtensa*-*-linux*
3012 NetBSD/hppa hppa*-*-netbsd*
3013 Xtensa GNU/Lunux xtensa*-*-linux*
3015 * Change in command line behavior -- corefiles vs. process ids.
3017 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3018 attaching to process NUMBER fails, GDB no longer attempts to open a
3019 core file named NUMBER. Attaching to a program using the -c option
3020 is no longer supported. Instead, use the '-p' or '--pid' options.
3022 * GDB can now be built as a native debugger for debugging Windows x86
3023 (mingw32) Portable Executable (PE) programs.
3025 * Pending breakpoints no longer change their number when their address
3028 * GDB now supports breakpoints with multiple locations,
3029 including breakpoints on C++ constructors, inside C++ templates,
3030 and in inlined functions.
3032 * GDB's ability to debug optimized code has been improved. GDB more
3033 accurately identifies function bodies and lexical blocks that occupy
3034 more than one contiguous range of addresses.
3036 * Target descriptions can now describe registers for PowerPC.
3038 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3039 registers on PowerPC targets.
3041 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3042 targets even when the libthread_db library is not available.
3044 * The GDB remote stub, gdbserver, now supports the new file transfer
3045 commands (remote put, remote get, and remote delete).
3047 * The GDB remote stub, gdbserver, now supports run and attach in
3048 extended-remote mode.
3050 * hppa*64*-*-hpux11* target broken
3051 The debugger is unable to start a program and fails with the following
3052 error: "Error trying to get information about dynamic linker".
3053 The gdb-6.7 release is also affected.
3055 * GDB now supports the --enable-targets= configure option to allow
3056 building a single GDB executable that supports multiple remote
3057 target architectures.
3059 * GDB now supports debugging C and C++ programs which use the
3060 Decimal Floating Point extension. In addition, the PowerPC target
3061 now has a set of pseudo-registers to inspect decimal float values
3062 stored in two consecutive float registers.
3064 * The -break-insert MI command can optionally create pending
3067 * Improved support for debugging Ada
3068 Many improvements to the Ada language support have been made. These
3070 - Better support for Ada2005 interface types
3071 - Improved handling of arrays and slices in general
3072 - Better support for Taft-amendment types
3073 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3075 - Improved command completion in Ada
3078 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3083 set print frame-arguments (all|scalars|none)
3084 show print frame-arguments
3085 The value of this variable can be changed to control which argument
3086 values should be printed by the debugger when displaying a frame.
3091 Transfer files to and from a remote target, and delete remote files.
3098 Transfer files to and from a remote target, and delete remote files.
3100 * New remote packets
3107 Open, close, read, write, and delete files on the remote system.
3110 Attach to an existing process on the remote system, in extended-remote
3114 Run a new process on the remote system, in extended-remote mode.
3116 *** Changes in GDB 6.7
3118 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3119 bfd, libiberty and opcodes, as revealed by static analysis donated by
3120 Coverity, Inc. (http://scan.coverity.com).
3122 * When looking up multiply-defined global symbols, GDB will now prefer the
3123 symbol definition in the current shared library if it was built using the
3124 -Bsymbolic linker option.
3126 * When the Text User Interface (TUI) is not configured, GDB will now
3127 recognize the -tui command-line option and print a message that the TUI
3130 * The GDB remote stub, gdbserver, now has lower overhead for high
3131 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3133 * GDB for MIPS targets now autodetects whether a remote target provides
3134 32-bit or 64-bit register values.
3136 * Support for C++ member pointers has been improved.
3138 * GDB now understands XML target descriptions, which specify the
3139 target's overall architecture. GDB can read a description from
3140 a local file or over the remote serial protocol.
3142 * Vectors of single-byte data use a new integer type which is not
3143 automatically displayed as character or string data.
3145 * The /s format now works with the print command. It displays
3146 arrays of single-byte integers and pointers to single-byte integers
3149 * Target descriptions can now describe target-specific registers,
3150 for architectures which have implemented the support (currently
3151 only ARM, M68K, and MIPS).
3153 * GDB and the GDB remote stub, gdbserver, now support the XScale
3156 * The GDB remote stub, gdbserver, has been updated to support
3157 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3158 has been rewritten to use the standard GDB remote protocol.
3160 * GDB can now step into C++ functions which are called through thunks.
3162 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3164 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3165 layout. It also supports a TextSeg= and DataSeg= response when only
3166 segment base addresses (rather than offsets) are available.
3168 * The /i format now outputs any trailing branch delay slot instructions
3169 immediately following the last instruction within the count specified.
3171 * The GDB remote protocol "T" stop reply packet now supports a
3172 "library" response. Combined with the new "qXfer:libraries:read"
3173 packet, this response allows GDB to debug shared libraries on targets
3174 where the operating system manages the list of loaded libraries (e.g.
3175 Windows and SymbianOS).
3177 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3178 (DLLs) on Windows and Windows CE targets.
3180 * GDB now supports a faster verification that a .debug file matches its binary
3181 according to its build-id signature, if the signature is present.
3187 Enable or disable hardware flow control (RTS/CTS) on the serial port
3188 when debugging using remote targets.
3190 set mem inaccessible-by-default
3191 show mem inaccessible-by-default
3192 If the target supplies a memory map, for instance via the remote
3193 protocol's "qXfer:memory-map:read" packet, setting this variable
3194 prevents GDB from accessing memory outside the memory map. This
3195 is useful for targets with memory mapped registers or which react
3196 badly to accesses of unmapped address space.
3198 set breakpoint auto-hw
3199 show breakpoint auto-hw
3200 If the target supplies a memory map, for instance via the remote
3201 protocol's "qXfer:memory-map:read" packet, setting this variable
3202 lets GDB use hardware breakpoints automatically for memory regions
3203 where it can not use software breakpoints. This covers both the
3204 "break" command and internal breakpoints used for other commands
3205 including "next" and "finish".
3208 catch exception unhandled
3209 Stop the program execution when Ada exceptions are raised.
3212 Stop the program execution when an Ada assertion failed.
3216 Set an alternate system root for target files. This is a more
3217 general version of "set solib-absolute-prefix", which is now
3218 an alias to "set sysroot".
3221 Provide extended SPU facility status information. This set of
3222 commands is available only when debugging the Cell/B.E. SPU
3225 * New native configurations
3227 OpenBSD/sh sh*-*openbsd*
3230 unset tdesc filename
3232 Use the specified local file as an XML target description, and do
3233 not query the target for its built-in description.
3237 OpenBSD/sh sh*-*-openbsd*
3238 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3239 Toshiba Media Processor mep-elf
3241 * New remote packets
3244 Ignore the specified signals; pass them directly to the debugged program
3245 without stopping other threads or reporting them to GDB.
3247 qXfer:features:read:
3248 Read an XML target description from the target, which describes its
3253 Read or write contents of an spufs file on the target system. These
3254 packets are available only on the Cell/B.E. SPU architecture.
3256 qXfer:libraries:read:
3257 Report the loaded shared libraries. Combined with new "T" packet
3258 response, this packet allows GDB to debug shared libraries on
3259 targets where the operating system manages the list of loaded
3260 libraries (e.g. Windows and SymbianOS).
3264 Support for these obsolete configurations has been removed.
3272 i[34567]86-*-lynxos*
3273 i[34567]86-*-netware*
3274 i[34567]86-*-sco3.2v5*
3275 i[34567]86-*-sco3.2v4*
3277 i[34567]86-*-sysv4.2*
3280 i[34567]86-*-unixware2*
3281 i[34567]86-*-unixware*
3290 * Other removed features
3297 Various m68k-only ROM monitors.
3304 Various Renesas ROM monitors and debugging interfaces for SH and
3309 Support for a Macraigor serial interface to on-chip debugging.
3310 GDB does not directly support the newer parallel or USB
3315 A debug information format. The predecessor to DWARF 2 and
3316 DWARF 3, which are still supported.
3318 Support for the HP aCC compiler on HP-UX/PA-RISC
3320 SOM-encapsulated symbolic debugging information, automatic
3321 invocation of pxdb, and the aCC custom C++ ABI. This does not
3322 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3323 with aCC can still be debugged on an assembly level.
3325 MIPS ".pdr" sections
3327 A MIPS-specific format used to describe stack frame layout
3328 in debugging information.
3332 GDB could work with an older version of Guile to debug
3333 the interpreter and Scheme programs running in it.
3335 set mips stack-arg-size
3336 set mips saved-gpreg-size
3338 Use "set mips abi" to control parameter passing for MIPS.
3340 *** Changes in GDB 6.6
3345 Cell Broadband Engine SPU spu-elf
3347 * GDB can now be configured as a cross-debugger targeting native Windows
3348 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3349 running on a Windows system over TCP/IP to debug Windows programs.
3351 * The GDB remote stub, gdbserver, has been updated to support Windows and
3352 Cygwin debugging. Both single-threaded and multi-threaded programs are
3355 * The "set trust-readonly-sections" command works again. This command was
3356 broken in GDB 6.3, 6.4, and 6.5.
3358 * The "load" command now supports writing to flash memory, if the remote
3359 stub provides the required support.
3361 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3362 longer requires symbolic debug information (e.g. DWARF-2).
3367 unset substitute-path
3368 show substitute-path
3369 Manage a list of substitution rules that GDB uses to rewrite the name
3370 of the directories where the sources are located. This can be useful
3371 for instance when the sources were moved to a different location
3372 between compilation and debugging.
3376 Print each CLI command as it is executed. Each command is prefixed with
3377 a number of `+' symbols representing the nesting depth.
3378 The source command now has a `-v' option to enable the same feature.
3382 The ARM Demon monitor support (RDP protocol, "target rdp").
3384 Kernel Object Display, an embedded debugging feature which only worked with
3385 an obsolete version of Cisco IOS.
3387 The 'set download-write-size' and 'show download-write-size' commands.
3389 * New remote packets
3392 Tell a stub about GDB client features, and request remote target features.
3393 The first feature implemented is PacketSize, which allows the target to
3394 specify the size of packets it can handle - to minimize the number of
3395 packets required and improve performance when connected to a remote
3399 Fetch an OS auxilliary vector from the remote stub. This packet is a
3400 more efficient replacement for qPart:auxv:read.
3402 qXfer:memory-map:read:
3403 Fetch a memory map from the remote stub, including information about
3404 RAM, ROM, and flash memory devices.
3409 Erase and program a flash memory device.
3411 * Removed remote packets
3414 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3415 used it, and only gdbserver implemented it.
3417 *** Changes in GDB 6.5
3421 Renesas M32C/M16C m32c-elf
3423 Morpho Technologies ms1 ms1-elf
3427 init-if-undefined Initialize a convenience variable, but
3428 only if it doesn't already have a value.
3430 The following commands are presently only implemented for native GNU/Linux:
3432 checkpoint Save a snapshot of the program state.
3434 restart <n> Return the program state to a
3435 previously saved state.
3437 info checkpoints List currently saved checkpoints.
3439 delete-checkpoint <n> Delete a previously saved checkpoint.
3441 set|show detach-on-fork Tell gdb whether to detach from a newly
3442 forked process, or to keep debugging it.
3444 info forks List forks of the user program that
3445 are available to be debugged.
3447 fork <n> Switch to debugging one of several
3448 forks of the user program that are
3449 available to be debugged.
3451 delete-fork <n> Delete a fork from the list of forks
3452 that are available to be debugged (and
3453 kill the forked process).
3455 detach-fork <n> Delete a fork from the list of forks
3456 that are available to be debugged (and
3457 allow the process to continue).
3461 Morpho Technologies ms2 ms1-elf
3463 * Improved Windows host support
3465 GDB now builds as a cross debugger hosted on i686-mingw32, including
3466 native console support, and remote communications using either
3467 network sockets or serial ports.
3469 * Improved Modula-2 language support
3471 GDB can now print most types in the Modula-2 syntax. This includes:
3472 basic types, set types, record types, enumerated types, range types,
3473 pointer types and ARRAY types. Procedure var parameters are correctly
3474 printed and hexadecimal addresses and character constants are also
3475 written in the Modula-2 syntax. Best results can be obtained by using
3476 GNU Modula-2 together with the -gdwarf-2 command line option.
3480 The ARM rdi-share module.
3482 The Netware NLM debug server.
3484 *** Changes in GDB 6.4
3486 * New native configurations
3488 OpenBSD/arm arm*-*-openbsd*
3489 OpenBSD/mips64 mips64-*-openbsd*
3493 Morpho Technologies ms1 ms1-elf
3495 * New command line options
3497 --batch-silent As for --batch, but totally silent.
3498 --return-child-result The debugger will exist with the same value
3499 the child (debugged) program exited with.
3500 --eval-command COMMAND, -ex COMMAND
3501 Execute a single GDB CLI command. This may be
3502 specified multiple times and in conjunction
3503 with the --command (-x) option.
3505 * Deprecated commands removed
3507 The following commands, that were deprecated in 2000, have been
3511 set|show arm disassembly-flavor set|show arm disassembler
3512 othernames set arm disassembler
3513 set|show remotedebug set|show debug remote
3514 set|show archdebug set|show debug arch
3515 set|show eventdebug set|show debug event
3518 * New BSD user-level threads support
3520 It is now possible to debug programs using the user-level threads
3521 library on OpenBSD and FreeBSD. Currently supported (target)
3524 FreeBSD/amd64 x86_64-*-freebsd*
3525 FreeBSD/i386 i386-*-freebsd*
3526 OpenBSD/i386 i386-*-openbsd*
3528 Note that the new kernel threads libraries introduced in FreeBSD 5.x
3529 are not yet supported.
3531 * New support for Matsushita MN10300 w/sim added
3532 (Work in progress). mn10300-elf.
3534 * REMOVED configurations and files
3536 VxWorks and the XDR protocol *-*-vxworks
3537 Motorola MCORE mcore-*-*
3538 National Semiconductor NS32000 ns32k-*-*
3540 * New "set print array-indexes" command
3542 After turning this setting "on", GDB prints the index of each element
3543 when displaying arrays. The default is "off" to preserve the previous
3546 * VAX floating point support
3548 GDB now supports the not-quite-ieee VAX F and D floating point formats.
3550 * User-defined command support
3552 In addition to using $arg0..$arg9 for argument passing, it is now possible
3553 to use $argc to determine now many arguments have been passed. See the
3554 section on user-defined commands in the user manual for more information.
3556 *** Changes in GDB 6.3:
3558 * New command line option
3560 GDB now accepts -l followed by a number to set the timeout for remote
3563 * GDB works with GCC -feliminate-dwarf2-dups
3565 GDB now supports a more compact representation of DWARF-2 debug
3566 information using DW_FORM_ref_addr references. These are produced
3567 by GCC with the option -feliminate-dwarf2-dups and also by some
3568 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
3569 to use -feliminate-dwarf2-dups.
3571 * Internationalization
3573 When supported by the host system, GDB will be built with
3574 internationalization (libintl). The task of marking up the sources is
3575 continued, we're looking forward to our first translation.
3579 Initial support for debugging programs compiled with the GNAT
3580 implementation of the Ada programming language has been integrated
3581 into GDB. In this release, support is limited to expression evaluation.
3583 * New native configurations
3585 GNU/Linux/m32r m32r-*-linux-gnu
3589 GDB's remote protocol now includes support for the 'p' packet. This
3590 packet is used to fetch individual registers from a remote inferior.
3592 * END-OF-LIFE registers[] compatibility module
3594 GDB's internal register infrastructure has been completely rewritten.
3595 The new infrastructure making possible the implementation of key new
3596 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
3599 GDB 6.3 will be the last release to include the the registers[]
3600 compatibility module that allowed out-of-date configurations to
3601 continue to work. This change directly impacts the following
3611 powerpc bdm protocol
3613 Unless there is activity to revive these configurations, they will be
3614 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
3616 * OBSOLETE configurations and files
3618 Configurations that have been declared obsolete in this release have
3619 been commented out. Unless there is activity to revive these
3620 configurations, the next release of GDB will have their sources
3621 permanently REMOVED.
3630 *** Changes in GDB 6.2.1:
3632 * MIPS `break main; run' gave an heuristic-fence-post warning
3634 When attempting to run even a simple program, a warning about
3635 heuristic-fence-post being hit would be reported. This problem has
3638 * MIPS IRIX 'long double' crashed GDB
3640 When examining a long double variable, GDB would get a segmentation
3641 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
3642 IRIX long double values).
3646 A bug in the VAX stack code was causing problems with the "next"
3647 command. This problem has been fixed.
3649 *** Changes in GDB 6.2:
3651 * Fix for ``many threads''
3653 On GNU/Linux systems that use the NPTL threads library, a program
3654 rapidly creating and deleting threads would confuse GDB leading to the
3657 ptrace: No such process.
3658 thread_db_get_info: cannot get thread info: generic error
3660 This problem has been fixed.
3662 * "-async" and "-noasync" options removed.
3664 Support for the broken "-noasync" option has been removed (it caused
3667 * New ``start'' command.
3669 This command runs the program until the begining of the main procedure.
3671 * New BSD Kernel Data Access Library (libkvm) interface
3673 Using ``target kvm'' it is now possible to debug kernel core dumps and
3674 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
3675 platforms. Currently supported (native-only) configurations are:
3677 FreeBSD/amd64 x86_64-*-freebsd*
3678 FreeBSD/i386 i?86-*-freebsd*
3679 NetBSD/i386 i?86-*-netbsd*
3680 NetBSD/m68k m68*-*-netbsd*
3681 NetBSD/sparc sparc-*-netbsd*
3682 OpenBSD/amd64 x86_64-*-openbsd*
3683 OpenBSD/i386 i?86-*-openbsd*
3684 OpenBSD/m68k m68*-openbsd*
3685 OpenBSD/sparc sparc-*-openbsd*
3687 * Signal trampoline code overhauled
3689 Many generic problems with GDB's signal handling code have been fixed.
3690 These include: backtraces through non-contiguous stacks; recognition
3691 of sa_sigaction signal trampolines; backtrace from a NULL pointer
3692 call; backtrace through a signal trampoline; step into and out of
3693 signal handlers; and single-stepping in the signal trampoline.
3695 Please note that kernel bugs are a limiting factor here. These
3696 features have been shown to work on an s390 GNU/Linux system that
3697 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
3699 * Cygwin support for DWARF 2 added.
3701 * New native configurations
3703 GNU/Linux/hppa hppa*-*-linux*
3704 OpenBSD/hppa hppa*-*-openbsd*
3705 OpenBSD/m68k m68*-*-openbsd*
3706 OpenBSD/m88k m88*-*-openbsd*
3707 OpenBSD/powerpc powerpc-*-openbsd*
3708 NetBSD/vax vax-*-netbsd*
3709 OpenBSD/vax vax-*-openbsd*
3711 * END-OF-LIFE frame compatibility module
3713 GDB's internal frame infrastructure has been completely rewritten.
3714 The new infrastructure making it possible to support key new features
3715 including DWARF 2 Call Frame Information. To aid in the task of
3716 migrating old configurations to this new infrastructure, a
3717 compatibility module, that allowed old configurations to continue to
3718 work, was also included.
3720 GDB 6.2 will be the last release to include this frame compatibility
3721 module. This change directly impacts the following configurations:
3731 Unless there is activity to revive these configurations, they will be
3732 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
3734 * REMOVED configurations and files
3736 Sun 3, running SunOS 3 m68*-*-sunos3*
3737 Sun 3, running SunOS 4 m68*-*-sunos4*
3738 Sun 2, running SunOS 3 m68000-*-sunos3*
3739 Sun 2, running SunOS 4 m68000-*-sunos4*
3740 Motorola 680x0 running LynxOS m68*-*-lynxos*
3741 AT&T 3b1/Unix pc m68*-att-*
3742 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3743 decstation mips-dec-* mips-little-*
3744 riscos mips-*-riscos* mips-*-sysv*
3745 sonymips mips-sony-*
3746 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3748 *** Changes in GDB 6.1.1:
3750 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
3752 The TUI (Text-mode User Interface) is now built as part of a default
3753 GDB configuration. It is enabled by either selecting the TUI with the
3754 command line option "-i=tui" or by running the separate "gdbtui"
3755 program. For more information on the TUI, see the manual "Debugging
3758 * Pending breakpoint support (also included in GDB 6.1)
3760 Support has been added to allow you to specify breakpoints in shared
3761 libraries that have not yet been loaded. If a breakpoint location
3762 cannot be found, and the "breakpoint pending" option is set to auto,
3763 GDB queries you if you wish to make the breakpoint pending on a future
3764 shared-library load. If and when GDB resolves the breakpoint symbol,
3765 the pending breakpoint is removed as one or more regular breakpoints
3768 Pending breakpoints are very useful for GCJ Java debugging.
3770 * Fixed ISO-C build problems
3772 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
3773 non ISO-C code that stopped them being built using a more strict ISO-C
3774 compiler (e.g., IBM's C compiler).
3776 * Fixed build problem on IRIX 5
3778 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
3779 wasn't able to compile compile on an IRIX 5 system.
3781 * Added execute permission to gdb/gdbserver/configure
3783 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3784 permission. This bug would cause configure to fail on a number of
3785 systems (Solaris, IRIX). Ref: server/519.
3787 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3789 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3790 has been updated to use constant array sizes.
3792 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3794 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3795 its generated DWARF Call Frame Info. This encoding was causing GDB to
3796 panic, that panic has been fixed. Ref: gdb/1628.
3798 * Fixed a problem when examining parameters in shared library code.
3800 When examining parameters in optimized shared library code generated
3801 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3802 not available''. GDB now correctly displays the variable's value.
3804 *** Changes in GDB 6.1:
3806 * Removed --with-mmalloc
3808 Support for the mmalloc memory manager has been removed, as it
3809 conflicted with the internal gdb byte cache.
3811 * Changes in AMD64 configurations
3813 The AMD64 target now includes the %cs and %ss registers. As a result
3814 the AMD64 remote protocol has changed; this affects the floating-point
3815 and SSE registers. If you rely on those registers for your debugging,
3816 you should upgrade gdbserver on the remote side.
3818 * Revised SPARC target
3820 The SPARC target has been completely revised, incorporating the
3821 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3822 support for LynxOS and SunOS 4 has been dropped. Calling functions
3823 from within GDB on operating systems with a non-executable stack
3824 (Solaris, OpenBSD) now works.
3828 GDB has a new C++ demangler which does a better job on the mangled
3829 names generated by current versions of g++. It also runs faster, so
3830 with this and other changes gdb should now start faster on large C++
3833 * DWARF 2 Location Expressions
3835 GDB support for location expressions has been extended to support function
3836 arguments and frame bases. Older versions of GDB could crash when they
3839 * C++ nested types and namespaces
3841 GDB's support for nested types and namespaces in C++ has been
3842 improved, especially if you use the DWARF 2 debugging format. (This
3843 is the default for recent versions of GCC on most platforms.)
3844 Specifically, if you have a class "Inner" defined within a class or
3845 namespace "Outer", then GDB realizes that the class's name is
3846 "Outer::Inner", not simply "Inner". This should greatly reduce the
3847 frequency of complaints about not finding RTTI symbols. In addition,
3848 if you are stopped at inside of a function defined within a namespace,
3849 GDB modifies its name lookup accordingly.
3851 * New native configurations
3853 NetBSD/amd64 x86_64-*-netbsd*
3854 OpenBSD/amd64 x86_64-*-openbsd*
3855 OpenBSD/alpha alpha*-*-openbsd*
3856 OpenBSD/sparc sparc-*-openbsd*
3857 OpenBSD/sparc64 sparc64-*-openbsd*
3859 * New debugging protocols
3861 M32R with SDI protocol m32r-*-elf*
3863 * "set prompt-escape-char" command deleted.
3865 The command "set prompt-escape-char" has been deleted. This command,
3866 and its very obscure effet on GDB's prompt, was never documented,
3867 tested, nor mentioned in the NEWS file.
3869 * OBSOLETE configurations and files
3871 Configurations that have been declared obsolete in this release have
3872 been commented out. Unless there is activity to revive these
3873 configurations, the next release of GDB will have their sources
3874 permanently REMOVED.
3876 Sun 3, running SunOS 3 m68*-*-sunos3*
3877 Sun 3, running SunOS 4 m68*-*-sunos4*
3878 Sun 2, running SunOS 3 m68000-*-sunos3*
3879 Sun 2, running SunOS 4 m68000-*-sunos4*
3880 Motorola 680x0 running LynxOS m68*-*-lynxos*
3881 AT&T 3b1/Unix pc m68*-att-*
3882 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3883 decstation mips-dec-* mips-little-*
3884 riscos mips-*-riscos* mips-*-sysv*
3885 sonymips mips-sony-*
3886 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3888 * REMOVED configurations and files
3890 SGI Irix-4.x mips-sgi-irix4 or iris4
3891 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3892 Z8000 simulator z8k-zilog-none or z8ksim
3893 Matsushita MN10200 w/simulator mn10200-*-*
3894 H8/500 simulator h8500-hitachi-hms or h8500hms
3895 HP/PA running BSD hppa*-*-bsd*
3896 HP/PA running OSF/1 hppa*-*-osf*
3897 HP/PA Pro target hppa*-*-pro*
3898 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3899 386BSD i[3456]86-*-bsd*
3900 Sequent family i[3456]86-sequent-sysv4*
3901 i[3456]86-sequent-sysv*
3902 i[3456]86-sequent-bsd*
3903 SPARC running LynxOS sparc-*-lynxos*
3904 SPARC running SunOS 4 sparc-*-sunos4*
3905 Tsqware Sparclet sparclet-*-*
3906 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3908 *** Changes in GDB 6.0:
3912 Support for debugging the Objective-C programming language has been
3913 integrated into GDB.
3915 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3917 DWARF 2's Call Frame Information makes available compiler generated
3918 information that more exactly describes the program's run-time stack.
3919 By using this information, GDB is able to provide more robust stack
3922 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3923 have been updated to use a new backtrace mechanism which includes
3924 DWARF 2 CFI support.
3928 GDB's remote protocol has been extended to include support for hosted
3929 file I/O (where the remote target uses GDB's file system). See GDB's
3930 remote protocol documentation for details.
3932 * All targets using the new architecture framework.
3934 All of GDB's targets have been updated to use the new internal
3935 architecture framework. The way is now open for future GDB releases
3936 to include cross-architecture native debugging support (i386 on amd64,
3939 * GNU/Linux's Thread Local Storage (TLS)
3941 GDB now includes support for for the GNU/Linux implementation of
3942 per-thread variables.
3944 * GNU/Linux's Native POSIX Thread Library (NPTL)
3946 GDB's thread code has been updated to work with either the new
3947 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3949 * Separate debug info.
3951 GDB, in conjunction with BINUTILS, now supports a mechanism for
3952 automatically loading debug information from a separate file. Instead
3953 of shipping full debug and non-debug versions of system libraries,
3954 system integrators can now instead ship just the stripped libraries
3955 and optional debug files.
3957 * DWARF 2 Location Expressions
3959 DWARF 2 Location Expressions allow the compiler to more completely
3960 describe the location of variables (even in optimized code) to the
3963 GDB now includes preliminary support for location expressions (support
3964 for DW_OP_piece is still missing).
3968 A number of long standing bugs that caused GDB to die while starting a
3969 Java application have been fixed. GDB's Java support is now
3970 considered "useable".
3972 * GNU/Linux support for fork, vfork, and exec.
3974 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3975 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3978 * GDB supports logging output to a file
3980 There are two new commands, "set logging" and "show logging", which can be
3981 used to capture GDB's output to a file.
3983 * The meaning of "detach" has changed for gdbserver
3985 The "detach" command will now resume the application, as documented. To
3986 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3989 * d10v, m68hc11 `regs' command deprecated
3991 The `info registers' command has been updated so that it displays the
3992 registers using a format identical to the old `regs' command.
3996 A new command, "maint set profile on/off", has been added. This command can
3997 be used to enable or disable profiling while running GDB, to profile a
3998 session or a set of commands. In addition there is a new configure switch,
3999 "--enable-profiling", which will cause GDB to be compiled with profiling
4000 data, for more informative profiling results.
4002 * Default MI syntax changed to "mi2".
4004 The default MI (machine interface) syntax, enabled by the command line
4005 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4006 "mi1", can be enabled by specifying the option "-i=mi1".
4008 Support for the original "mi0" syntax (included in GDB 5.0) has been
4011 Fix for gdb/192: removed extraneous space when displaying frame level.
4012 Fix for gdb/672: update changelist is now output in mi list format.
4013 Fix for gdb/702: a -var-assign that updates the value now shows up
4014 in a subsequent -var-update.
4016 * New native configurations.
4018 FreeBSD/amd64 x86_64-*-freebsd*
4020 * Multi-arched targets.
4022 HP/PA HPUX11 hppa*-*-hpux*
4023 Renesas M32R/D w/simulator m32r-*-elf*
4025 * OBSOLETE configurations and files
4027 Configurations that have been declared obsolete in this release have
4028 been commented out. Unless there is activity to revive these
4029 configurations, the next release of GDB will have their sources
4030 permanently REMOVED.
4032 Z8000 simulator z8k-zilog-none or z8ksim
4033 Matsushita MN10200 w/simulator mn10200-*-*
4034 H8/500 simulator h8500-hitachi-hms or h8500hms
4035 HP/PA running BSD hppa*-*-bsd*
4036 HP/PA running OSF/1 hppa*-*-osf*
4037 HP/PA Pro target hppa*-*-pro*
4038 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4039 Sequent family i[3456]86-sequent-sysv4*
4040 i[3456]86-sequent-sysv*
4041 i[3456]86-sequent-bsd*
4042 Tsqware Sparclet sparclet-*-*
4043 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4045 * REMOVED configurations and files
4048 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4049 IBM AIX PS/2 i[3456]86-*-aix
4050 i386 running Mach 3.0 i[3456]86-*-mach3*
4051 i386 running Mach i[3456]86-*-mach*
4052 i386 running OSF/1 i[3456]86-*osf1mk*
4053 HP/Apollo 68k Family m68*-apollo*-sysv*,
4055 m68*-hp-bsd*, m68*-hp-hpux*
4056 Argonaut Risc Chip (ARC) arc-*-*
4057 Mitsubishi D30V d30v-*-*
4058 Fujitsu FR30 fr30-*-elf*
4059 OS/9000 i[34]86-*-os9k
4060 I960 with MON960 i960-*-coff
4062 * MIPS $fp behavior changed
4064 The convenience variable $fp, for the MIPS, now consistently returns
4065 the address of the current frame's base. Previously, depending on the
4066 context, $fp could refer to either $sp or the current frame's base
4067 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4068 The GNU Source-Level Debugger''.
4070 *** Changes in GDB 5.3:
4072 * GNU/Linux shared library multi-threaded performance improved.
4074 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4075 `/proc', in preference to `ptrace' for memory reads. This may result
4076 in an improvement in the start-up time of multi-threaded, shared
4077 library applications when run under GDB. One GDB user writes: ``loads
4078 shared libs like mad''.
4080 * ``gdbserver'' now supports multi-threaded applications on some targets
4082 Support for debugging multi-threaded applications which use
4083 the GNU/Linux LinuxThreads package has been added for
4084 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4085 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4087 * GDB now supports C/C++ preprocessor macros.
4089 GDB now expands preprocessor macro invocations in C/C++ expressions,
4090 and provides various commands for showing macro definitions and how
4093 The new command `macro expand EXPRESSION' expands any macro
4094 invocations in expression, and shows the result.
4096 The new command `show macro MACRO-NAME' shows the definition of the
4097 macro named MACRO-NAME, and where it was defined.
4099 Most compilers don't include information about macros in the debugging
4100 information by default. In GCC 3.1, for example, you need to compile
4101 your program with the options `-gdwarf-2 -g3'. If the macro
4102 information is present in the executable, GDB will read it.
4104 * Multi-arched targets.
4106 DEC Alpha (partial) alpha*-*-*
4107 DEC VAX (partial) vax-*-*
4109 National Semiconductor NS32000 (partial) ns32k-*-*
4110 Motorola 68000 (partial) m68k-*-*
4111 Motorola MCORE mcore-*-*
4115 Fujitsu FRV architecture added by Red Hat frv*-*-*
4118 * New native configurations
4120 Alpha NetBSD alpha*-*-netbsd*
4121 SH NetBSD sh*-*-netbsdelf*
4122 MIPS NetBSD mips*-*-netbsd*
4123 UltraSPARC NetBSD sparc64-*-netbsd*
4125 * OBSOLETE configurations and files
4127 Configurations that have been declared obsolete in this release have
4128 been commented out. Unless there is activity to revive these
4129 configurations, the next release of GDB will have their sources
4130 permanently REMOVED.
4132 Mitsubishi D30V d30v-*-*
4133 OS/9000 i[34]86-*-os9k
4134 IBM AIX PS/2 i[3456]86-*-aix
4135 Fujitsu FR30 fr30-*-elf*
4136 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4137 Argonaut Risc Chip (ARC) arc-*-*
4138 i386 running Mach 3.0 i[3456]86-*-mach3*
4139 i386 running Mach i[3456]86-*-mach*
4140 i386 running OSF/1 i[3456]86-*osf1mk*
4141 HP/Apollo 68k Family m68*-apollo*-sysv*,
4143 m68*-hp-bsd*, m68*-hp-hpux*
4144 I960 with MON960 i960-*-coff
4146 * OBSOLETE languages
4148 CHILL, a Pascal like language used by telecommunications companies.
4150 * REMOVED configurations and files
4152 AMD 29k family via UDI a29k-amd-udi, udi29k
4153 A29K VxWorks a29k-*-vxworks
4154 AMD 29000 embedded, using EBMON a29k-none-none
4155 AMD 29000 embedded with COFF a29k-none-coff
4156 AMD 29000 embedded with a.out a29k-none-aout
4158 testsuite/gdb.hp/gdb.threads-hp/ directory
4160 * New command "set max-user-call-depth <nnn>"
4162 This command allows the user to limit the call depth of user-defined
4163 commands. The default is 1024.
4165 * Changes in FreeBSD/i386 native debugging.
4167 Support for the "generate-core-file" has been added.
4169 * New commands "dump", "append", and "restore".
4171 These commands allow data to be copied from target memory
4172 to a bfd-format or binary file (dump and append), and back
4173 from a file into memory (restore).
4175 * Improved "next/step" support on multi-processor Alpha Tru64.
4177 The previous single-step mechanism could cause unpredictable problems,
4178 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4179 of a software single-step mechanism prevents this.
4181 *** Changes in GDB 5.2.1:
4189 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4190 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4191 Fix, by Joel Brobecker imported from mainline.
4193 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4194 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4195 Fix, by Fred Fish, imported from mainline.
4197 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4198 Surprisingly enough, it works now.
4199 By Michal Ludvig, imported from mainline.
4201 i386 hardware watchpoint support:
4202 avoid misses on second run for some targets.
4203 By Pierre Muller, imported from mainline.
4205 *** Changes in GDB 5.2:
4207 * New command "set trust-readonly-sections on[off]".
4209 This command is a hint that tells gdb that read-only sections
4210 really are read-only (ie. that their contents will not change).
4211 In this mode, gdb will go to the object file rather than the
4212 target to read memory from read-only sections (such as ".text").
4213 This can be a significant performance improvement on some
4214 (notably embedded) targets.
4216 * New command "generate-core-file" (or "gcore").
4218 This new gdb command allows the user to drop a core file of the child
4219 process state at any time. So far it's been implemented only for
4220 GNU/Linux and Solaris, but should be relatively easily ported to other
4221 hosts. Argument is core file name (defaults to core.<pid>).
4223 * New command line option
4225 GDB now accepts --pid or -p followed by a process id.
4227 * Change in command line behavior -- corefiles vs. process ids.
4229 There is a subtle behavior in the way in which GDB handles
4230 command line arguments. The first non-flag argument is always
4231 a program to debug, but the second non-flag argument may either
4232 be a corefile or a process id. Previously, GDB would attempt to
4233 open the second argument as a corefile, and if that failed, would
4234 issue a superfluous error message and then attempt to attach it as
4235 a process. Now, if the second argument begins with a non-digit,
4236 it will be treated as a corefile. If it begins with a digit,
4237 GDB will attempt to attach it as a process, and if no such process
4238 is found, will then attempt to open it as a corefile.
4240 * Changes in ARM configurations.
4242 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4243 configuration is fully multi-arch.
4245 * New native configurations
4247 ARM NetBSD arm*-*-netbsd*
4248 x86 OpenBSD i[3456]86-*-openbsd*
4249 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4250 Sparc64 running FreeBSD sparc64-*-freebsd*
4254 Sanyo XStormy16 xstormy16-elf
4256 * OBSOLETE configurations and files
4258 Configurations that have been declared obsolete in this release have
4259 been commented out. Unless there is activity to revive these
4260 configurations, the next release of GDB will have their sources
4261 permanently REMOVED.
4263 AMD 29k family via UDI a29k-amd-udi, udi29k
4264 A29K VxWorks a29k-*-vxworks
4265 AMD 29000 embedded, using EBMON a29k-none-none
4266 AMD 29000 embedded with COFF a29k-none-coff
4267 AMD 29000 embedded with a.out a29k-none-aout
4269 testsuite/gdb.hp/gdb.threads-hp/ directory
4271 * REMOVED configurations and files
4273 TI TMS320C80 tic80-*-*
4275 PowerPC Solaris powerpcle-*-solaris*
4276 PowerPC Windows NT powerpcle-*-cygwin32
4277 PowerPC Netware powerpc-*-netware*
4278 Harris/CXUX m88k m88*-harris-cxux*
4279 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4280 ns32k-utek-sysv* ns32k-utek-*
4281 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4282 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4283 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4284 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4285 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4287 * Changes to command line processing
4289 The new `--args' feature can be used to specify command-line arguments
4290 for the inferior from gdb's command line.
4292 * Changes to key bindings
4294 There is a new `operate-and-get-next' function bound to `C-o'.
4296 *** Changes in GDB 5.1.1
4298 Fix compile problem on DJGPP.
4300 Fix a problem with floating-point registers on the i386 being
4303 Fix to stop GDB crashing on .debug_str debug info.
4305 Numerous documentation fixes.
4307 Numerous testsuite fixes.
4309 *** Changes in GDB 5.1:
4311 * New native configurations
4313 Alpha FreeBSD alpha*-*-freebsd*
4314 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4315 MIPS GNU/Linux mips*-*-linux*
4316 MIPS SGI Irix 6.x mips*-sgi-irix6*
4317 ia64 AIX ia64-*-aix*
4318 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4322 Motorola 68HC11 and 68HC12 m68hc11-elf
4324 UltraSparc running GNU/Linux sparc64-*-linux*
4326 * OBSOLETE configurations and files
4328 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4329 Harris/CXUX m88k m88*-harris-cxux*
4330 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4331 ns32k-utek-sysv* ns32k-utek-*
4332 TI TMS320C80 tic80-*-*
4334 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4335 PowerPC Solaris powerpcle-*-solaris*
4336 PowerPC Windows NT powerpcle-*-cygwin32
4337 PowerPC Netware powerpc-*-netware*
4338 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4339 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4340 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4341 Apple Macintosh (MPW) host N/A
4343 stuff.c (Program to stuff files into a specially prepared space in kdb)
4344 kdb-start.c (Main loop for the standalone kernel debugger)
4346 Configurations that have been declared obsolete in this release have
4347 been commented out. Unless there is activity to revive these
4348 configurations, the next release of GDB will have their sources
4349 permanently REMOVED.
4351 * REMOVED configurations and files
4353 Altos 3068 m68*-altos-*
4354 Convex c1-*-*, c2-*-*
4356 ARM RISCix arm-*-* (as host)
4360 * GDB has been converted to ISO C.
4362 GDB's source code has been converted to ISO C. In particular, the
4363 sources are fully protoized, and rely on standard headers being
4368 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4370 * The MI enabled by default.
4372 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4373 revised and enabled by default. Packages which use GDB as a debugging
4374 engine behind a UI or another front end are encouraged to switch to
4375 using the GDB/MI interface, instead of the old annotations interface
4376 which is now deprecated.
4378 * Support for debugging Pascal programs.
4380 GDB now includes support for debugging Pascal programs. The following
4381 main features are supported:
4383 - Pascal-specific data types such as sets;
4385 - automatic recognition of Pascal sources based on file-name
4388 - Pascal-style display of data types, variables, and functions;
4390 - a Pascal expression parser.
4392 However, some important features are not yet supported.
4394 - Pascal string operations are not supported at all;
4396 - there are some problems with boolean types;
4398 - Pascal type hexadecimal constants are not supported
4399 because they conflict with the internal variables format;
4401 - support for Pascal objects and classes is not full yet;
4403 - unlike Pascal, GDB is case-sensitive for symbol names.
4405 * Changes in completion.
4407 Commands such as `shell', `run' and `set args', which pass arguments
4408 to inferior programs, now complete on file names, similar to what
4409 users expect at the shell prompt.
4411 Commands which accept locations, such as `disassemble', `print',
4412 `breakpoint', `until', etc. now complete on filenames as well as
4413 program symbols. Thus, if you type "break foob TAB", and the source
4414 files linked into the programs include `foobar.c', that file name will
4415 be one of the candidates for completion. However, file names are not
4416 considered for completion after you typed a colon that delimits a file
4417 name from a name of a function in that file, as in "break foo.c:bar".
4419 `set demangle-style' completes on available demangling styles.
4421 * New platform-independent commands:
4423 It is now possible to define a post-hook for a command as well as a
4424 hook that runs before the command. For more details, see the
4425 documentation of `hookpost' in the GDB manual.
4427 * Changes in GNU/Linux native debugging.
4429 Support for debugging multi-threaded programs has been completely
4430 revised for all platforms except m68k and sparc. You can now debug as
4431 many threads as your system allows you to have.
4433 Attach/detach is supported for multi-threaded programs.
4435 Support for SSE registers was added for x86. This doesn't work for
4436 multi-threaded programs though.
4438 * Changes in MIPS configurations.
4440 Multi-arch support is enabled for all MIPS configurations.
4442 GDB can now be built as native debugger on SGI Irix 6.x systems for
4443 debugging n32 executables. (Debugging 64-bit executables is not yet
4446 * Unified support for hardware watchpoints in all x86 configurations.
4448 Most (if not all) native x86 configurations support hardware-assisted
4449 breakpoints and watchpoints in a unified manner. This support
4450 implements debug register sharing between watchpoints, which allows to
4451 put a virtually infinite number of watchpoints on the same address,
4452 and also supports watching regions up to 16 bytes with several debug
4455 The new maintenance command `maintenance show-debug-regs' toggles
4456 debugging print-outs in functions that insert, remove, and test
4457 watchpoints and hardware breakpoints.
4459 * Changes in the DJGPP native configuration.
4461 New command ``info dos sysinfo'' displays assorted information about
4462 the CPU, OS, memory, and DPMI server.
4464 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
4465 display information about segment descriptors stored in GDT, LDT, and
4468 New commands ``info dos pde'' and ``info dos pte'' display entries
4469 from Page Directory and Page Tables (for now works with CWSDPMI only).
4470 New command ``info dos address-pte'' displays the Page Table entry for
4471 a given linear address.
4473 GDB can now pass command lines longer than 126 characters to the
4474 program being debugged (requires an update to the libdbg.a library
4475 which is part of the DJGPP development kit).
4477 DWARF2 debug info is now supported.
4479 It is now possible to `step' and `next' through calls to `longjmp'.
4481 * Changes in documentation.
4483 All GDB documentation was converted to GFDL, the GNU Free
4484 Documentation License.
4486 Tracepoints-related commands are now fully documented in the GDB
4489 TUI, the Text-mode User Interface, is now documented in the manual.
4491 Tracepoints-related commands are now fully documented in the GDB
4494 The "GDB Internals" manual now has an index. It also includes
4495 documentation of `ui_out' functions, GDB coding standards, x86
4496 hardware watchpoints, and memory region attributes.
4498 * GDB's version number moved to ``version.in''
4500 The Makefile variable VERSION has been replaced by the file
4501 ``version.in''. People creating GDB distributions should update the
4502 contents of this file.
4506 GUD support is now a standard part of the EMACS distribution.
4508 *** Changes in GDB 5.0:
4510 * Improved support for debugging FP programs on x86 targets
4512 Unified and much-improved support for debugging floating-point
4513 programs on all x86 targets. In particular, ``info float'' now
4514 displays the FP registers in the same format on all x86 targets, with
4515 greater level of detail.
4517 * Improvements and bugfixes in hardware-assisted watchpoints
4519 It is now possible to watch array elements, struct members, and
4520 bitfields with hardware-assisted watchpoints. Data-read watchpoints
4521 on x86 targets no longer erroneously trigger when the address is
4524 * Improvements in the native DJGPP version of GDB
4526 The distribution now includes all the scripts and auxiliary files
4527 necessary to build the native DJGPP version on MS-DOS/MS-Windows
4528 machines ``out of the box''.
4530 The DJGPP version can now debug programs that use signals. It is
4531 possible to catch signals that happened in the debuggee, deliver
4532 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
4533 would kill the program being debugged.) Programs that hook hardware
4534 interrupts (keyboard, timer, etc.) can also be debugged.
4536 It is now possible to debug DJGPP programs that redirect their
4537 standard handles or switch them to raw (as opposed to cooked) mode, or
4538 even close them. The command ``run < foo > bar'' works as expected,
4539 and ``info terminal'' reports useful information about the debuggee's
4540 terminal, including raw/cooked mode, redirection, etc.
4542 The DJGPP version now uses termios functions for console I/O, which
4543 enables debugging graphics programs. Interrupting GDB with Ctrl-C
4546 DOS-style file names with drive letters are now fully supported by
4549 It is now possible to debug DJGPP programs that switch their working
4550 directory. It is also possible to rerun the debuggee any number of
4551 times without restarting GDB; thus, you can use the same setup,
4552 breakpoints, etc. for many debugging sessions.
4554 * New native configurations
4556 ARM GNU/Linux arm*-*-linux*
4557 PowerPC GNU/Linux powerpc-*-linux*
4561 Motorola MCore mcore-*-*
4562 x86 VxWorks i[3456]86-*-vxworks*
4563 PowerPC VxWorks powerpc-*-vxworks*
4564 TI TMS320C80 tic80-*-*
4566 * OBSOLETE configurations
4568 Altos 3068 m68*-altos-*
4569 Convex c1-*-*, c2-*-*
4571 ARM RISCix arm-*-* (as host)
4574 Configurations that have been declared obsolete will be commented out,
4575 but the code will be left in place. If there is no activity to revive
4576 these configurations before the next release of GDB, the sources will
4577 be permanently REMOVED.
4579 * Gould support removed
4581 Support for the Gould PowerNode and NP1 has been removed.
4583 * New features for SVR4
4585 On SVR4 native platforms (such as Solaris), if you attach to a process
4586 without first loading a symbol file, GDB will now attempt to locate and
4587 load symbols from the running process's executable file.
4589 * Many C++ enhancements
4591 C++ support has been greatly improved. Overload resolution now works properly
4592 in almost all cases. RTTI support is on the way.
4594 * Remote targets can connect to a sub-program
4596 A popen(3) style serial-device has been added. This device starts a
4597 sub-process (such as a stand-alone simulator) and then communicates
4598 with that. The sub-program to run is specified using the syntax
4599 ``|<program> <args>'' vis:
4601 (gdb) set remotedebug 1
4602 (gdb) target extended-remote |mn10300-elf-sim program-args
4604 * MIPS 64 remote protocol
4606 A long standing bug in the mips64 remote protocol where by GDB
4607 expected certain 32 bit registers (ex SR) to be transfered as 32
4608 instead of 64 bits has been fixed.
4610 The command ``set remote-mips64-transfers-32bit-regs on'' has been
4611 added to provide backward compatibility with older versions of GDB.
4613 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
4615 The command ``set remotebinarydownload'' command has been replaced by
4616 ``set remote X-packet''. Other commands in ``set remote'' family
4617 include ``set remote P-packet''.
4619 * Breakpoint commands accept ranges.
4621 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
4622 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
4623 ``tracepoint passcount'' also accepts a range of tracepoints.
4625 * ``apropos'' command added.
4627 The ``apropos'' command searches through command names and
4628 documentation strings, printing out matches, making it much easier to
4629 try to find a command that does what you are looking for.
4633 A new machine oriented interface (MI) has been added to GDB. This
4634 interface is designed for debug environments running GDB as a separate
4635 process. This is part of the long term libGDB project. See the
4636 "GDB/MI" chapter of the GDB manual for further information. It can be
4637 enabled by configuring with:
4639 .../configure --enable-gdbmi
4641 *** Changes in GDB-4.18:
4643 * New native configurations
4645 HP-UX 10.20 hppa*-*-hpux10.20
4646 HP-UX 11.x hppa*-*-hpux11.0*
4647 M68K GNU/Linux m68*-*-linux*
4651 Fujitsu FR30 fr30-*-elf*
4652 Intel StrongARM strongarm-*-*
4653 Mitsubishi D30V d30v-*-*
4655 * OBSOLETE configurations
4657 Gould PowerNode, NP1 np1-*-*, pn-*-*
4659 Configurations that have been declared obsolete will be commented out,
4660 but the code will be left in place. If there is no activity to revive
4661 these configurations before the next release of GDB, the sources will
4662 be permanently REMOVED.
4666 As a compatibility experiment, GDB's source files buildsym.h and
4667 buildsym.c have been converted to pure standard C, no longer
4668 containing any K&R compatibility code. We believe that all systems in
4669 use today either come with a standard C compiler, or have a GCC port
4670 available. If this is not true, please report the affected
4671 configuration to bug-gdb@gnu.org immediately. See the README file for
4672 information about getting a standard C compiler if you don't have one
4677 GDB now uses readline 2.2.
4679 * set extension-language
4681 You can now control the mapping between filename extensions and source
4682 languages by using the `set extension-language' command. For instance,
4683 you can ask GDB to treat .c files as C++ by saying
4684 set extension-language .c c++
4685 The command `info extensions' lists all of the recognized extensions
4686 and their associated languages.
4688 * Setting processor type for PowerPC and RS/6000
4690 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
4691 you can use the `set processor' command to specify what variant of the
4692 PowerPC family you are debugging. The command
4696 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
4697 following PowerPC and RS6000 variants:
4699 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
4700 rs6000 IBM RS6000 ("POWER") architecture, user-level view
4702 403GC IBM PowerPC 403GC
4703 505 Motorola PowerPC 505
4704 860 Motorola PowerPC 860 or 850
4705 601 Motorola PowerPC 601
4706 602 Motorola PowerPC 602
4707 603 Motorola/IBM PowerPC 603 or 603e
4708 604 Motorola PowerPC 604 or 604e
4709 750 Motorola/IBM PowerPC 750 or 750
4711 At the moment, this command just tells GDB what to name the
4712 special-purpose processor registers. Since almost all the affected
4713 registers are inaccessible to user-level programs, this command is
4714 only useful for remote debugging in its present form.
4718 Thanks to a major code donation from Hewlett-Packard, GDB now has much
4719 more extensive support for HP-UX. Added features include shared
4720 library support, kernel threads and hardware watchpoints for 11.00,
4721 support for HP's ANSI C and C++ compilers, and a compatibility mode
4722 for xdb and dbx commands.
4726 HP's donation includes the new concept of catchpoints, which is a
4727 generalization of the old catch command. On HP-UX, it is now possible
4728 to catch exec, fork, and vfork, as well as library loading.
4730 This means that the existing catch command has changed; its first
4731 argument now specifies the type of catch to be set up. See the
4732 output of "help catch" for a list of catchpoint types.
4734 * Debugging across forks
4736 On HP-UX, you can choose which process to debug when a fork() happens
4741 HP has donated a curses-based terminal user interface (TUI). To get
4742 it, build with --enable-tui. Although this can be enabled for any
4743 configuration, at present it only works for native HP debugging.
4745 * GDB remote protocol additions
4747 A new protocol packet 'X' that writes binary data is now available.
4748 Default behavior is to try 'X', then drop back to 'M' if the stub
4749 fails to respond. The settable variable `remotebinarydownload'
4750 allows explicit control over the use of 'X'.
4752 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
4753 full 64-bit address. The command
4755 set remoteaddresssize 32
4757 can be used to revert to the old behaviour. For existing remote stubs
4758 the change should not be noticed, as the additional address information
4761 In order to assist in debugging stubs, you may use the maintenance
4762 command `packet' to send any text string to the stub. For instance,
4764 maint packet heythere
4766 sends the packet "$heythere#<checksum>". Note that it is very easy to
4767 disrupt a debugging session by sending the wrong packet at the wrong
4770 The compare-sections command allows you to compare section data on the
4771 target to what is in the executable file without uploading or
4772 downloading, by comparing CRC checksums.
4774 * Tracing can collect general expressions
4776 You may now collect general expressions at tracepoints. This requires
4777 further additions to the target-side stub; see tracepoint.c and
4778 doc/agentexpr.texi for further details.
4780 * mask-address variable for Mips
4782 For Mips targets, you may control the zeroing of the upper 32 bits of
4783 a 64-bit address by entering `set mask-address on'. This is mainly
4784 of interest to users of embedded R4xxx and R5xxx processors.
4786 * Higher serial baud rates
4788 GDB's serial code now allows you to specify baud rates 57600, 115200,
4789 230400, and 460800 baud. (Note that your host system may not be able
4790 to achieve all of these rates.)
4794 The i960 configuration now includes an initial implementation of a
4795 builtin simulator, contributed by Jim Wilson.
4798 *** Changes in GDB-4.17:
4800 * New native configurations
4802 Alpha GNU/Linux alpha*-*-linux*
4803 Unixware 2.x i[3456]86-unixware2*
4804 Irix 6.x mips*-sgi-irix6*
4805 PowerPC GNU/Linux powerpc-*-linux*
4806 PowerPC Solaris powerpcle-*-solaris*
4807 Sparc GNU/Linux sparc-*-linux*
4808 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4812 Argonaut Risc Chip (ARC) arc-*-*
4813 Hitachi H8/300S h8300*-*-*
4814 Matsushita MN10200 w/simulator mn10200-*-*
4815 Matsushita MN10300 w/simulator mn10300-*-*
4816 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4817 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4818 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4819 Mitsubishi D10V w/simulator d10v-*-*
4820 Mitsubishi M32R/D w/simulator m32r-*-elf*
4821 Tsqware Sparclet sparclet-*-*
4822 NEC V850 w/simulator v850-*-*
4824 * New debugging protocols
4826 ARM with RDI protocol arm*-*-*
4827 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4828 DDB and LSI variants of PMON protocol mips*-*-*
4829 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4830 PowerPC with SDS protocol powerpc{,le}-*-eabi
4831 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4835 All configurations can now understand and use the DWARF 2 debugging
4836 format. The choice is automatic, if the symbol file contains DWARF 2
4841 GDB now includes basic Java language support. This support is
4842 only useful with Java compilers that produce native machine code.
4844 * solib-absolute-prefix and solib-search-path
4846 For SunOS and SVR4 shared libraries, you may now set the prefix for
4847 loading absolute shared library symbol files, and the search path for
4848 locating non-absolute shared library symbol files.
4850 * Live range splitting
4852 GDB can now effectively debug code for which GCC has performed live
4853 range splitting as part of its optimization. See gdb/doc/LRS for
4854 more details on the expected format of the stabs information.
4858 GDB's support for the GNU Hurd, including thread debugging, has been
4859 updated to work with current versions of the Hurd.
4863 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4864 instruction set. ARM GDB automatically detects when Thumb
4865 instructions are in use, and adjusts disassembly and backtracing
4870 GDB's MIPS target configurations now handle the MIP16 16-bit
4875 GDB now includes support for overlays; if an executable has been
4876 linked such that multiple sections are based at the same address, GDB
4877 will decide which section to use for symbolic info. You can choose to
4878 control the decision manually, using overlay commands, or implement
4879 additional target-side support and use "overlay load-target" to bring
4880 in the overlay mapping. Do "help overlay" for more detail.
4884 The command "info symbol <address>" displays information about
4885 the symbol at the specified address.
4889 The standard remote protocol now includes an extension that allows
4890 asynchronous collection and display of trace data. This requires
4891 extensive support in the target-side debugging stub. Tracing mode
4892 includes a new interaction mode in GDB and new commands: see the
4893 file tracepoint.c for more details.
4897 Configurations for embedded MIPS now include a simulator contributed
4898 by Cygnus Solutions. The simulator supports the instruction sets
4899 of most MIPS variants.
4903 Sparc configurations may now include the ERC32 simulator contributed
4904 by the European Space Agency. The simulator is not built into
4905 Sparc targets by default; configure with --enable-sim to include it.
4909 For target configurations that may include multiple variants of a
4910 basic architecture (such as MIPS and SH), you may now set the
4911 architecture explicitly. "set arch" sets, "info arch" lists
4912 the possible architectures.
4914 *** Changes in GDB-4.16:
4916 * New native configurations
4918 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4919 M68K NetBSD m68k-*-netbsd*
4920 PowerPC AIX 4.x powerpc-*-aix*
4921 PowerPC MacOS powerpc-*-macos*
4922 PowerPC Windows NT powerpcle-*-cygwin32
4923 RS/6000 AIX 4.x rs6000-*-aix4*
4927 ARM with RDP protocol arm-*-*
4928 I960 with MON960 i960-*-coff
4929 MIPS VxWorks mips*-*-vxworks*
4930 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4931 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4933 Matra Sparclet sparclet-*-*
4937 The powerpc-eabi configuration now includes the PSIM simulator,
4938 contributed by Andrew Cagney, with assistance from Mike Meissner.
4939 PSIM is a very elaborate model of the PowerPC, including not only
4940 basic instruction set execution, but also details of execution unit
4941 performance and I/O hardware. See sim/ppc/README for more details.
4945 GDB now works with Solaris 2.5.
4947 * Windows 95/NT native
4949 GDB will now work as a native debugger on Windows 95 and Windows NT.
4950 To build it from source, you must use the "gnu-win32" environment,
4951 which uses a DLL to emulate enough of Unix to run the GNU tools.
4952 Further information, binaries, and sources are available at
4953 ftp.cygnus.com, under pub/gnu-win32.
4955 * dont-repeat command
4957 If a user-defined command includes the command `dont-repeat', then the
4958 command will not be repeated if the user just types return. This is
4959 useful if the command is time-consuming to run, so that accidental
4960 extra keystrokes don't run the same command many times.
4962 * Send break instead of ^C
4964 The standard remote protocol now includes an option to send a break
4965 rather than a ^C to the target in order to interrupt it. By default,
4966 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4968 * Remote protocol timeout
4970 The standard remote protocol includes a new variable `remotetimeout'
4971 that allows you to set the number of seconds before GDB gives up trying
4972 to read from the target. The default value is 2.
4974 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4976 By default GDB will automatically keep track of objects as they are
4977 loaded and unloaded by the dynamic linker. By using the command `set
4978 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4979 when shared library events occur, thus allowing you to set breakpoints
4980 in shared libraries which are explicitly loaded by the inferior.
4982 Note this feature does not work on hpux8. On hpux9 you must link
4983 /usr/lib/end.o into your program. This feature should work
4984 automatically on hpux10.
4986 * Irix 5.x hardware watchpoint support
4988 Irix 5 configurations now support the use of hardware watchpoints.
4990 * Mips protocol "SYN garbage limit"
4992 When debugging a Mips target using the `target mips' protocol, you
4993 may set the number of characters that GDB will ignore by setting
4994 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4995 every character. The default value is 1050.
4997 * Recording and replaying remote debug sessions
4999 If you set `remotelogfile' to the name of a file, gdb will write to it
5000 a recording of a remote debug session. This recording may then be
5001 replayed back to gdb using "gdbreplay". See gdbserver/README for
5002 details. This is useful when you have a problem with GDB while doing
5003 remote debugging; you can make a recording of the session and send it
5004 to someone else, who can then recreate the problem.
5006 * Speedups for remote debugging
5008 GDB includes speedups for downloading and stepping MIPS systems using
5009 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5010 and more efficient S-record downloading.
5012 * Memory use reductions and statistics collection
5014 GDB now uses less memory and reports statistics about memory usage.
5015 Try the `maint print statistics' command, for example.
5017 *** Changes in GDB-4.15:
5019 * Psymtabs for XCOFF
5021 The symbol reader for AIX GDB now uses partial symbol tables. This
5022 can greatly improve startup time, especially for large executables.
5024 * Remote targets use caching
5026 Remote targets now use a data cache to speed up communication with the
5027 remote side. The data cache could lead to incorrect results because
5028 it doesn't know about volatile variables, thus making it impossible to
5029 debug targets which use memory mapped I/O devices. `set remotecache
5030 off' turns the the data cache off.
5032 * Remote targets may have threads
5034 The standard remote protocol now includes support for multiple threads
5035 in the target system, using new protocol commands 'H' and 'T'. See
5036 gdb/remote.c for details.
5040 If GDB is configured with `--enable-netrom', then it will include
5041 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5042 acts as though it is a bank of ROM on the target board, but you can
5043 write into it over the network. GDB's support consists only of
5044 support for fast loading into the emulated ROM; to debug, you must use
5045 another protocol, such as standard remote protocol. The usual
5046 sequence is something like
5048 target nrom <netrom-hostname>
5050 target remote <netrom-hostname>:1235
5054 GDB now includes support for the Apple Macintosh, as a host only. It
5055 may be run as either an MPW tool or as a standalone application, and
5056 it can debug through the serial port. All the usual GDB commands are
5057 available, but to the target command, you must supply "serial" as the
5058 device type instead of "/dev/ttyXX". See mpw-README in the main
5059 directory for more information on how to build. The MPW configuration
5060 scripts */mpw-config.in support only a few targets, and only the
5061 mips-idt-ecoff target has been tested.
5065 GDB configuration now uses autoconf. This is not user-visible,
5066 but does simplify configuration and building.
5070 GDB now supports hpux10.
5072 *** Changes in GDB-4.14:
5074 * New native configurations
5076 x86 FreeBSD i[345]86-*-freebsd
5077 x86 NetBSD i[345]86-*-netbsd
5078 NS32k NetBSD ns32k-*-netbsd
5079 Sparc NetBSD sparc-*-netbsd
5083 A29K VxWorks a29k-*-vxworks
5084 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5085 CPU32 EST-300 emulator m68*-*-est*
5086 PowerPC ELF powerpc-*-elf
5089 * Alpha OSF/1 support for procfs
5091 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5092 possible to attach to running processes. As the mounting of the /proc
5093 filesystem is optional on the Alpha, GDB automatically determines
5094 the availability of /proc during startup. This can lead to problems
5095 if /proc is unmounted after GDB has been started.
5097 * Arguments to user-defined commands
5099 User commands may accept up to 10 arguments separated by whitespace.
5100 Arguments are accessed within the user command via $arg0..$arg9. A
5103 print $arg0 + $arg1 + $arg2
5105 To execute the command use:
5108 Defines the command "adder" which prints the sum of its three arguments.
5109 Note the arguments are text substitutions, so they may reference variables,
5110 use complex expressions, or even perform inferior function calls.
5112 * New `if' and `while' commands
5114 This makes it possible to write more sophisticated user-defined
5115 commands. Both commands take a single argument, which is the
5116 expression to evaluate, and must be followed by the commands to
5117 execute, one per line, if the expression is nonzero, the list being
5118 terminated by the word `end'. The `if' command list may include an
5119 `else' word, which causes the following commands to be executed only
5120 if the expression is zero.
5122 * Fortran source language mode
5124 GDB now includes partial support for Fortran 77. It will recognize
5125 Fortran programs and can evaluate a subset of Fortran expressions, but
5126 variables and functions may not be handled correctly. GDB will work
5127 with G77, but does not yet know much about symbols emitted by other
5130 * Better HPUX support
5132 Most debugging facilities now work on dynamic executables for HPPAs
5133 running hpux9 or later. You can attach to running dynamically linked
5134 processes, but by default the dynamic libraries will be read-only, so
5135 for instance you won't be able to put breakpoints in them. To change
5136 that behavior do the following before running the program:
5142 This will cause the libraries to be mapped private and read-write.
5143 To revert to the normal behavior, do this:
5149 You cannot set breakpoints or examine data in the library until after
5150 the library is loaded if the function/data symbols do not have
5153 GDB can now also read debug symbols produced by the HP C compiler on
5154 HPPAs (sorry, no C++, Fortran or 68k support).
5156 * Target byte order now dynamically selectable
5158 You can choose which byte order to use with a target system, via the
5159 commands "set endian big" and "set endian little", and you can see the
5160 current setting by using "show endian". You can also give the command
5161 "set endian auto", in which case GDB will use the byte order
5162 associated with the executable. Currently, only embedded MIPS
5163 configurations support dynamic selection of target byte order.
5165 * New DOS host serial code
5167 This version uses DPMI interrupts to handle buffered I/O, so you
5168 no longer need to run asynctsr when debugging boards connected to
5171 *** Changes in GDB-4.13:
5173 * New "complete" command
5175 This lists all the possible completions for the rest of the line, if it
5176 were to be given as a command itself. This is intended for use by emacs.
5178 * Trailing space optional in prompt
5180 "set prompt" no longer adds a space for you after the prompt you set. This
5181 allows you to set a prompt which ends in a space or one that does not.
5183 * Breakpoint hit counts
5185 "info break" now displays a count of the number of times the breakpoint
5186 has been hit. This is especially useful in conjunction with "ignore"; you
5187 can ignore a large number of breakpoint hits, look at the breakpoint info
5188 to see how many times the breakpoint was hit, then run again, ignoring one
5189 less than that number, and this will get you quickly to the last hit of
5192 * Ability to stop printing at NULL character
5194 "set print null-stop" will cause GDB to stop printing the characters of
5195 an array when the first NULL is encountered. This is useful when large
5196 arrays actually contain only short strings.
5198 * Shared library breakpoints
5200 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5201 breakpoints in shared libraries before the executable is run.
5203 * Hardware watchpoints
5205 There is a new hardware breakpoint for the watch command for sparclite
5206 targets. See gdb/sparclite/hw_breakpoint.note.
5208 Hardware watchpoints are also now supported under GNU/Linux.
5212 Annotations have been added. These are for use with graphical interfaces,
5213 and are still experimental. Currently only gdba.el uses these.
5215 * Improved Irix 5 support
5217 GDB now works properly with Irix 5.2.
5219 * Improved HPPA support
5221 GDB now works properly with the latest GCC and GAS.
5223 * New native configurations
5225 Sequent PTX4 i[34]86-sequent-ptx4
5226 HPPA running OSF/1 hppa*-*-osf*
5227 Atari TT running SVR4 m68*-*-sysv4*
5228 RS/6000 LynxOS rs6000-*-lynxos*
5232 OS/9000 i[34]86-*-os9k
5233 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5236 * Hitachi SH7000 and E7000-PC ICE support
5238 There is now support for communicating with the Hitachi E7000-PC ICE.
5239 This is available automatically when GDB is configured for the SH.
5243 As usual, a variety of small fixes and improvements, both generic
5244 and configuration-specific. See the ChangeLog for more detail.
5246 *** Changes in GDB-4.12:
5248 * Irix 5 is now supported
5252 GDB-4.12 on the HPPA has a number of changes which make it unable
5253 to debug the output from the currently released versions of GCC and
5254 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5255 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5256 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5259 *** Changes in GDB-4.11:
5261 * User visible changes:
5265 The "set remotedebug" option is now consistent between the mips remote
5266 target, remote targets using the gdb-specific protocol, UDI (AMD's
5267 debug protocol for the 29k) and the 88k bug monitor. It is now an
5268 integer specifying a debug level (normally 0 or 1, but 2 means more
5269 debugging info for the mips target).
5271 * DEC Alpha native support
5273 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5274 debug info, but GDB works fairly well with the DEC compiler and should
5275 work with a future GCC release. See the README file for a few
5276 Alpha-specific notes.
5278 * Preliminary thread implementation
5280 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5282 * LynxOS native and target support for 386
5284 This release has been hosted on LynxOS 2.2, and also can be configured
5285 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5288 * Improvements in C++ mangling/demangling.
5290 This release has much better g++ debugging, specifically in name
5291 mangling/demangling, virtual function calls, print virtual table,
5292 call methods, ...etc.
5294 *** Changes in GDB-4.10:
5296 * User visible changes:
5298 Remote debugging using the GDB-specific (`target remote') protocol now
5299 supports the `load' command. This is only useful if you have some
5300 other way of getting the stub to the target system, and you can put it
5301 somewhere in memory where it won't get clobbered by the download.
5303 Filename completion now works.
5305 When run under emacs mode, the "info line" command now causes the
5306 arrow to point to the line specified. Also, "info line" prints
5307 addresses in symbolic form (as well as hex).
5309 All vxworks based targets now support a user settable option, called
5310 vxworks-timeout. This option represents the number of seconds gdb
5311 should wait for responses to rpc's. You might want to use this if
5312 your vxworks target is, perhaps, a slow software simulator or happens
5313 to be on the far side of a thin network line.
5317 This release contains support for using a DEC alpha as a GDB host for
5318 cross debugging. Native alpha debugging is not supported yet.
5321 *** Changes in GDB-4.9:
5325 This is the first GDB release which is accompanied by a matching testsuite.
5326 The testsuite requires installation of dejagnu, which should be available
5327 via ftp from most sites that carry GNU software.
5331 'Cfront' style demangling has had its name changed to 'ARM' style, to
5332 emphasize that it was written from the specifications in the C++ Annotated
5333 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5334 disclaimers, it still generated too much confusion with users attempting to
5335 use gdb with AT&T cfront.
5339 GDB now uses a standard remote interface to a simulator library.
5340 So far, the library contains simulators for the Zilog Z8001/2, the
5341 Hitachi H8/300, H8/500 and Super-H.
5343 * New targets supported
5345 H8/300 simulator h8300-hitachi-hms or h8300hms
5346 H8/500 simulator h8500-hitachi-hms or h8500hms
5347 SH simulator sh-hitachi-hms or sh
5348 Z8000 simulator z8k-zilog-none or z8ksim
5349 IDT MIPS board over serial line mips-idt-ecoff
5351 Cross-debugging to GO32 targets is supported. It requires a custom
5352 version of the i386-stub.c module which is integrated with the
5353 GO32 memory extender.
5355 * New remote protocols
5357 MIPS remote debugging protocol.
5359 * New source languages supported
5361 This version includes preliminary support for Chill, a Pascal like language
5362 used by telecommunications companies. Chill support is also being integrated
5363 into the GNU compiler, but we don't know when it will be publically available.
5366 *** Changes in GDB-4.8:
5368 * HP Precision Architecture supported
5370 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5371 version of this support was available as a set of patches from the
5372 University of Utah. GDB does not support debugging of programs
5373 compiled with the HP compiler, because HP will not document their file
5374 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5375 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5377 Many problems in the preliminary version have been fixed.
5379 * Faster and better demangling
5381 We have improved template demangling and fixed numerous bugs in the GNU style
5382 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5383 character types (wchar_t) are now supported. Demangling of each symbol is now
5384 only done once, and is cached when the symbol table for a file is read in.
5385 This results in a small increase in memory usage for C programs, a moderate
5386 increase in memory usage for C++ programs, and a fantastic speedup in
5389 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5390 from the specifications in the Annotated Reference Manual, which AT&T's
5391 compiler does not actually implement.
5393 * G++ multiple inheritance compiler problem
5395 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5396 inheritance lattices was reworked to properly discover ambiguities. We
5397 recently found an example which causes this new algorithm to fail in a
5398 very subtle way, producing bad debug information for those classes.
5399 The file 'gcc.patch' (in this directory) can be applied to gcc to
5400 circumvent the problem. A future GCC release will contain a complete
5403 The previous G++ debug info problem (mentioned below for the gdb-4.7
5404 release) is fixed in gcc version 2.3.2.
5406 * Improved configure script
5408 The `configure' script will now attempt to guess your system type if
5409 you don't supply a host system type. The old scheme of supplying a
5410 host system triplet is preferable over using this. All the magic is
5411 done in the new `config.guess' script. Examine it for details.
5413 We have also brought our configure script much more in line with the FSF's
5414 version. It now supports the --with-xxx options. In particular,
5415 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5416 The resulting GDB will not be able to read arbitrary object file formats --
5417 only the format ``expected'' to be used on the configured target system.
5418 We hope to make this the default in a future release.
5420 * Documentation improvements
5422 There's new internal documentation on how to modify GDB, and how to
5423 produce clean changes to the code. We implore people to read it
5424 before submitting changes.
5426 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5427 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5428 `info' files are also provided. To build `info' files from scratch,
5429 you will need the latest `makeinfo' release, which will be available in
5430 a future texinfo-X.Y release.
5432 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5433 We're not sure exactly which versions have this problem, but it has
5434 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5435 or better. If that isn't possible, there is a patch in
5436 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5437 around this problem.
5441 GDB now supports array constants that can be used in expressions typed in by
5442 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5443 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
5446 The new directory `gdb/sparclite' contains a program that demonstrates
5447 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
5449 * New native hosts supported
5451 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
5452 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
5454 * New targets supported
5456 AMD 29k family via UDI a29k-amd-udi or udi29k
5458 * New file formats supported
5460 BFD now supports reading HP/PA-RISC executables (SOM file format?),
5461 HPUX core files, and SCO 3.2v2 core files.
5465 Attaching to processes now works again; thanks for the many bug reports.
5467 We have also stomped on a bunch of core dumps caused by
5468 printf_filtered("%s") problems.
5470 We eliminated a copyright problem on the rpc and ptrace header files
5471 for VxWorks, which was discovered at the last minute during the 4.7
5472 release. You should now be able to build a VxWorks GDB.
5474 You can now interrupt gdb while an attached process is running. This
5475 will cause the attached process to stop, and give control back to GDB.
5477 We fixed problems caused by using too many file descriptors
5478 for reading symbols from object files and libraries. This was
5479 especially a problem for programs that used many (~100) shared
5482 The `step' command now only enters a subroutine if there is line number
5483 information for the subroutine. Otherwise it acts like the `next'
5484 command. Previously, `step' would enter subroutines if there was
5485 any debugging information about the routine. This avoids problems
5486 when using `cc -g1' on MIPS machines.
5488 * Internal improvements
5490 GDB's internal interfaces have been improved to make it easier to support
5491 debugging of multiple languages in the future.
5493 GDB now uses a common structure for symbol information internally.
5494 Minimal symbols (derived from linkage symbols in object files), partial
5495 symbols (from a quick scan of debug information), and full symbols
5496 contain a common subset of information, making it easier to write
5497 shared code that handles any of them.
5499 * New command line options
5501 We now accept --silent as an alias for --quiet.
5505 The memory-mapped-malloc library is now licensed under the GNU Library
5506 General Public License.
5508 *** Changes in GDB-4.7:
5510 * Host/native/target split
5512 GDB has had some major internal surgery to untangle the support for
5513 hosts and remote targets. Now, when you configure GDB for a remote
5514 target, it will no longer load in all of the support for debugging
5515 local programs on the host. When fully completed and tested, this will
5516 ensure that arbitrary host/target combinations are possible.
5518 The primary conceptual shift is to separate the non-portable code in
5519 GDB into three categories. Host specific code is required any time GDB
5520 is compiled on that host, regardless of the target. Target specific
5521 code relates to the peculiarities of the target, but can be compiled on
5522 any host. Native specific code is everything else: it can only be
5523 built when the host and target are the same system. Child process
5524 handling and core file support are two common `native' examples.
5526 GDB's use of /proc for controlling Unix child processes is now cleaner.
5527 It has been split out into a single module under the `target_ops' vector,
5528 plus two native-dependent functions for each system that uses /proc.
5530 * New hosts supported
5532 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
5533 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5534 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
5536 * New targets supported
5538 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5539 68030 and CPU32 m68030-*-*, m68332-*-*
5541 * New native hosts supported
5543 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
5544 (386bsd is not well tested yet)
5545 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
5547 * New file formats supported
5549 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
5550 supports reading of `a.out.adobe' object files, which are an a.out
5551 format extended with minimal information about multiple sections.
5555 `show copying' is the same as the old `info copying'.
5556 `show warranty' is the same as `info warrantee'.
5557 These were renamed for consistency. The old commands continue to work.
5559 `info handle' is a new alias for `info signals'.
5561 You can now define pre-command hooks, which attach arbitrary command
5562 scripts to any command. The commands in the hook will be executed
5563 prior to the user's command. You can also create a hook which will be
5564 executed whenever the program stops. See gdb.texinfo.
5568 We now deal with Cfront style name mangling, and can even extract type
5569 info from mangled symbols. GDB can automatically figure out which
5570 symbol mangling style your C++ compiler uses.
5572 Calling of methods and virtual functions has been improved as well.
5576 The crash that occured when debugging Sun Ansi-C compiled binaries is
5577 fixed. This was due to mishandling of the extra N_SO stabs output
5580 We also finally got Ultrix 4.2 running in house, and fixed core file
5581 support, with help from a dozen people on the net.
5583 John M. Farrell discovered that the reason that single-stepping was so
5584 slow on all of the Mips based platforms (primarily SGI and DEC) was
5585 that we were trying to demangle and lookup a symbol used for internal
5586 purposes on every instruction that was being stepped through. Changing
5587 the name of that symbol so that it couldn't be mistaken for a C++
5588 mangled symbol sped things up a great deal.
5590 Rich Pixley sped up symbol lookups in general by getting much smarter
5591 about when C++ symbol mangling is necessary. This should make symbol
5592 completion (TAB on the command line) much faster. It's not as fast as
5593 we'd like, but it's significantly faster than gdb-4.6.
5597 A new user controllable variable 'call_scratch_address' can
5598 specify the location of a scratch area to be used when GDB
5599 calls a function in the target. This is necessary because the
5600 usual method of putting the scratch area on the stack does not work
5601 in systems that have separate instruction and data spaces.
5603 We integrated changes to support the 29k UDI (Universal Debugger
5604 Interface), but discovered at the last minute that we didn't have all
5605 of the appropriate copyright paperwork. We are working with AMD to
5606 resolve this, and hope to have it available soon.
5610 We have sped up the remote serial line protocol, especially for targets
5611 with lots of registers. It now supports a new `expedited status' ('T')
5612 message which can be used in place of the existing 'S' status message.
5613 This allows the remote stub to send only the registers that GDB
5614 needs to make a quick decision about single-stepping or conditional
5615 breakpoints, eliminating the need to fetch the entire register set for
5616 each instruction being stepped through.
5618 The GDB remote serial protocol now implements a write-through cache for
5619 registers, only re-reading the registers if the target has run.
5621 There is also a new remote serial stub for SPARC processors. You can
5622 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
5623 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
5624 processor with a serial port.
5628 Configure.in files have become much easier to read and modify. A new
5629 `table driven' format makes it more obvious what configurations are
5630 supported, and what files each one uses.
5634 There is a new opcodes library which will eventually contain all of the
5635 disassembly routines and opcode tables. At present, it only contains
5636 Sparc and Z8000 routines. This will allow the assembler, debugger, and
5637 disassembler (binutils/objdump) to share these routines.
5639 The libiberty library is now copylefted under the GNU Library General
5640 Public License. This allows more liberal use, and was done so libg++
5641 can use it. This makes no difference to GDB, since the Library License
5642 grants all the rights from the General Public License.
5646 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
5647 reference to the stabs symbol info used by the debugger. It is (as far
5648 as we know) the only published document on this fascinating topic. We
5649 encourage you to read it, compare it to the stabs information on your
5650 system, and send improvements on the document in general (to
5651 bug-gdb@prep.ai.mit.edu).
5653 And, of course, many bugs have been fixed.
5656 *** Changes in GDB-4.6:
5658 * Better support for C++ function names
5660 GDB now accepts as input the "demangled form" of C++ overloaded function
5661 names and member function names, and can do command completion on such names
5662 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
5663 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
5664 Make use of command completion, it is your friend.
5666 GDB also now accepts a variety of C++ mangled symbol formats. They are
5667 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
5668 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
5669 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
5670 for the list of formats.
5672 * G++ symbol mangling problem
5674 Recent versions of gcc have a bug in how they emit debugging information for
5675 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
5676 directory) can be applied to gcc to fix the problem. Alternatively, if you
5677 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
5678 usual symptom is difficulty with setting breakpoints on methods. GDB complains
5679 about the method being non-existent. (We believe that version 2.2.2 of GCC has
5682 * New 'maintenance' command
5684 All of the commands related to hacking GDB internals have been moved out of
5685 the main command set, and now live behind the 'maintenance' command. This
5686 can also be abbreviated as 'mt'. The following changes were made:
5688 dump-me -> maintenance dump-me
5689 info all-breakpoints -> maintenance info breakpoints
5690 printmsyms -> maintenance print msyms
5691 printobjfiles -> maintenance print objfiles
5692 printpsyms -> maintenance print psymbols
5693 printsyms -> maintenance print symbols
5695 The following commands are new:
5697 maintenance demangle Call internal GDB demangler routine to
5698 demangle a C++ link name and prints the result.
5699 maintenance print type Print a type chain for a given symbol
5701 * Change to .gdbinit file processing
5703 We now read the $HOME/.gdbinit file before processing the argv arguments
5704 (e.g. reading symbol files or core files). This allows global parameters to
5705 be set, which will apply during the symbol reading. The ./.gdbinit is still
5706 read after argv processing.
5708 * New hosts supported
5710 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
5712 GNU/Linux support i386-unknown-linux or linux
5714 We are also including code to support the HP/PA running BSD and HPUX. This
5715 is almost guaranteed not to work, as we didn't have time to test or build it
5716 for this release. We are including it so that the more adventurous (or
5717 masochistic) of you can play with it. We also had major problems with the
5718 fact that the compiler that we got from HP doesn't support the -g option.
5721 * New targets supported
5723 Hitachi H8/300 h8300-hitachi-hms or h8300hms
5725 * More smarts about finding #include files
5727 GDB now remembers the compilation directory for all include files, and for
5728 all files from which C is generated (like yacc and lex sources). This
5729 greatly improves GDB's ability to find yacc/lex sources, and include files,
5730 especially if you are debugging your program from a directory different from
5731 the one that contains your sources.
5733 We also fixed a bug which caused difficulty with listing and setting
5734 breakpoints in include files which contain C code. (In the past, you had to
5735 try twice in order to list an include file that you hadn't looked at before.)
5737 * Interesting infernals change
5739 GDB now deals with arbitrary numbers of sections, where the symbols for each
5740 section must be relocated relative to that section's landing place in the
5741 target's address space. This work was needed to support ELF with embedded
5742 stabs used by Solaris-2.0.
5744 * Bug fixes (of course!)
5746 There have been loads of fixes for the following things:
5747 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
5748 i960, stabs, DOS(GO32), procfs, etc...
5750 See the ChangeLog for details.
5752 *** Changes in GDB-4.5:
5754 * New machines supported (host and target)
5756 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
5758 SGI Irix-4.x mips-sgi-irix4 or iris4
5760 * New malloc package
5762 GDB now uses a new memory manager called mmalloc, based on gmalloc.
5763 Mmalloc is capable of handling mutiple heaps of memory. It is also
5764 capable of saving a heap to a file, and then mapping it back in later.
5765 This can be used to greatly speedup the startup of GDB by using a
5766 pre-parsed symbol table which lives in a mmalloc managed heap. For
5767 more details, please read mmalloc/mmalloc.texi.
5771 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
5772 'help info proc' for details.
5774 * MIPS ecoff symbol table format
5776 The code that reads MIPS symbol table format is now supported on all hosts.
5777 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5780 * File name changes for MS-DOS
5782 Many files in the config directories have been renamed to make it easier to
5783 support GDB on MS-DOSe systems (which have very restrictive file name
5784 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5785 environment) is close to working but has some remaining problems. Note
5786 that debugging of DOS programs is not supported, due to limitations
5787 in the ``operating system'', but it can be used to host cross-debugging.
5789 * Cross byte order fixes
5791 Many fixes have been made to support cross debugging of Sparc and MIPS
5792 targets from hosts whose byte order differs.
5794 * New -mapped and -readnow options
5796 If memory-mapped files are available on your system through the 'mmap'
5797 system call, you can use the -mapped option on the `file' or
5798 `symbol-file' commands to cause GDB to write the symbols from your
5799 program into a reusable file. If the program you are debugging is
5800 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5801 Future GDB debugging sessions will notice the presence of this file,
5802 and will quickly map in symbol information from it, rather than reading
5803 the symbol table from the executable program. Using the '-mapped'
5804 option in a GDB `file' or `symbol-file' command has the same effect as
5805 starting GDB with the '-mapped' command-line option.
5807 You can cause GDB to read the entire symbol table immediately by using
5808 the '-readnow' option with any of the commands that load symbol table
5809 information (or on the GDB command line). This makes the command
5810 slower, but makes future operations faster.
5812 The -mapped and -readnow options are typically combined in order to
5813 build a `fred.syms' file that contains complete symbol information.
5814 A simple GDB invocation to do nothing but build a `.syms' file for future
5817 gdb -batch -nx -mapped -readnow programname
5819 The `.syms' file is specific to the host machine on which GDB is run.
5820 It holds an exact image of GDB's internal symbol table. It cannot be
5821 shared across multiple host platforms.
5823 * longjmp() handling
5825 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5826 siglongjmp() without losing control. This feature has not yet been ported to
5827 all systems. It currently works on many 386 platforms, all MIPS-based
5828 platforms (SGI, DECstation, etc), and Sun3/4.
5832 Preliminary work has been put in to support the new Solaris OS from Sun. At
5833 this time, it can control and debug processes, but it is not capable of
5838 As always, many many bug fixes. The major areas were with g++, and mipsread.
5839 People using the MIPS-based platforms should experience fewer mysterious
5840 crashes and trashed symbol tables.
5842 *** Changes in GDB-4.4:
5844 * New machines supported (host and target)
5846 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5848 BSD Reno on Vax vax-dec-bsd
5849 Ultrix on Vax vax-dec-ultrix
5851 * New machines supported (target)
5853 AMD 29000 embedded, using EBMON a29k-none-none
5857 GDB continues to improve its handling of C++. `References' work better.
5858 The demangler has also been improved, and now deals with symbols mangled as
5859 per the Annotated C++ Reference Guide.
5861 GDB also now handles `stabs' symbol information embedded in MIPS
5862 `ecoff' symbol tables. Since the ecoff format was not easily
5863 extensible to handle new languages such as C++, this appeared to be a
5864 good way to put C++ debugging info into MIPS binaries. This option
5865 will be supported in the GNU C compiler, version 2, when it is
5868 * New features for SVR4
5870 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5871 shared libraries. Debugging dynamically linked programs should present
5872 only minor differences from debugging statically linked programs.
5874 The `info proc' command will print out information about any process
5875 on an SVR4 system (including the one you are debugging). At the moment,
5876 it prints the address mappings of the process.
5878 If you bring up GDB on another SVR4 system, please send mail to
5879 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5881 * Better dynamic linking support in SunOS
5883 Reading symbols from shared libraries which contain debugging symbols
5884 now works properly. However, there remain issues such as automatic
5885 skipping of `transfer vector' code during function calls, which
5886 make it harder to debug code in a shared library, than to debug the
5887 same code linked statically.
5891 GDB is now using the latest `getopt' routines from the FSF. This
5892 version accepts the -- prefix for options with long names. GDB will
5893 continue to accept the old forms (-option and +option) as well.
5894 Various single letter abbreviations for options have been explicity
5895 added to the option table so that they won't get overshadowed in the
5896 future by other options that begin with the same letter.
5900 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5901 Many assorted bugs have been handled. Many more remain to be handled.
5902 See the various ChangeLog files (primarily in gdb and bfd) for details.
5905 *** Changes in GDB-4.3:
5907 * New machines supported (host and target)
5909 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5910 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5911 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5913 * Almost SCO Unix support
5915 We had hoped to support:
5916 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5917 (except for core file support), but we discovered very late in the release
5918 that it has problems with process groups that render gdb unusable. Sorry
5919 about that. I encourage people to fix it and post the fixes.
5921 * Preliminary ELF and DWARF support
5923 GDB can read ELF object files on System V Release 4, and can handle
5924 debugging records for C, in DWARF format, in ELF files. This support
5925 is preliminary. If you bring up GDB on another SVR4 system, please
5926 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5931 GDB now uses the latest `readline' library. One user-visible change
5932 is that two tabs will list possible command completions, which previously
5933 required typing M-? (meta-question mark, or ESC ?).
5937 The `stepi' bug that many of you noticed has been squashed.
5938 Many bugs in C++ have been handled. Many more remain to be handled.
5939 See the various ChangeLog files (primarily in gdb and bfd) for details.
5941 * State of the MIPS world (in case you wondered):
5943 GDB can understand the symbol tables emitted by the compilers
5944 supplied by most vendors of MIPS-based machines, including DEC. These
5945 symbol tables are in a format that essentially nobody else uses.
5947 Some versions of gcc come with an assembler post-processor called
5948 mips-tfile. This program is required if you want to do source-level
5949 debugging of gcc-compiled programs. I believe FSF does not ship
5950 mips-tfile with gcc version 1, but it will eventually come with gcc
5953 Debugging of g++ output remains a problem. g++ version 1.xx does not
5954 really support it at all. (If you're lucky, you should be able to get
5955 line numbers and stack traces to work, but no parameters or local
5956 variables.) With some work it should be possible to improve the
5959 When gcc version 2 is released, you will have somewhat better luck.
5960 However, even then you will get confusing results for inheritance and
5963 We will eventually provide full debugging of g++ output on
5964 DECstations. This will probably involve some kind of stabs-in-ecoff
5965 encapulation, but the details have not been worked out yet.
5968 *** Changes in GDB-4.2:
5970 * Improved configuration
5972 Only one copy of `configure' exists now, and it is not self-modifying.
5973 Porting BFD is simpler.
5977 The `step' and `next' commands now only stop at the first instruction
5978 of a source line. This prevents the multiple stops that used to occur
5979 in switch statements, for-loops, etc. `Step' continues to stop if a
5980 function that has debugging information is called within the line.
5984 Lots of small bugs fixed. More remain.
5986 * New host supported (not target)
5988 Intel 386 PC clone running Mach i386-none-mach
5991 *** Changes in GDB-4.1:
5993 * Multiple source language support
5995 GDB now has internal scaffolding to handle several source languages.
5996 It determines the type of each source file from its filename extension,
5997 and will switch expression parsing and number formatting to match the
5998 language of the function in the currently selected stack frame.
5999 You can also specifically set the language to be used, with
6000 `set language c' or `set language modula-2'.
6004 GDB now has preliminary support for the GNU Modula-2 compiler,
6005 currently under development at the State University of New York at
6006 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6007 continue through the fall of 1991 and into 1992.
6009 Other Modula-2 compilers are currently not supported, and attempting to
6010 debug programs compiled with them will likely result in an error as the
6011 symbol table is read. Feel free to work on it, though!
6013 There are hooks in GDB for strict type checking and range checking,
6014 in the `Modula-2 philosophy', but they do not currently work.
6018 GDB can now write to executable and core files (e.g. patch
6019 a variable's value). You must turn this switch on, specify
6020 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6021 by assigning a new value to a variable. Modifications take
6024 * Automatic SunOS shared library reading
6026 When you run your program, GDB automatically determines where its
6027 shared libraries (if any) have been loaded, and reads their symbols.
6028 The `share' command is no longer needed. This also works when
6029 examining core files.
6033 You can specify the number of lines that the `list' command shows.
6036 * New machines supported (host and target)
6038 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6039 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6040 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6042 * New hosts supported (not targets)
6044 IBM RT/PC: romp-ibm-aix or rtpc
6046 * New targets supported (not hosts)
6048 AMD 29000 embedded with COFF a29k-none-coff
6049 AMD 29000 embedded with a.out a29k-none-aout
6050 Ultracomputer remote kernel debug a29k-nyu-kern
6052 * New remote interfaces
6058 *** Changes in GDB-4.0:
6062 Wide output is wrapped at good places to make the output more readable.
6064 Gdb now supports cross-debugging from a host machine of one type to a
6065 target machine of another type. Communication with the target system
6066 is over serial lines. The ``target'' command handles connecting to the
6067 remote system; the ``load'' command will download a program into the
6068 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6069 also supports debugging of realtime processes running under VxWorks,
6070 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6071 stub on the target system.
6073 New CPUs supported include the AMD 29000 and Intel 960.
6075 GDB now reads object files and symbol tables via a ``binary file''
6076 library, which allows a single copy of GDB to debug programs of multiple
6077 object file types such as a.out and coff.
6079 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6080 refcard.dvi and refcard.ps are available to format it).
6083 * Control-Variable user interface simplified
6085 All variables that control the operation of the debugger can be set
6086 by the ``set'' command, and displayed by the ``show'' command.
6088 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6089 ``Show prompt'' produces the response:
6090 Gdb's prompt is new-gdb=>.
6092 What follows are the NEW set commands. The command ``help set'' will
6093 print a complete list of old and new set commands. ``help set FOO''
6094 will give a longer description of the variable FOO. ``show'' will show
6095 all of the variable descriptions and their current settings.
6097 confirm on/off: Enables warning questions for operations that are
6098 hard to recover from, e.g. rerunning the program while
6099 it is already running. Default is ON.
6101 editing on/off: Enables EMACS style command line editing
6102 of input. Previous lines can be recalled with
6103 control-P, the current line can be edited with control-B,
6104 you can search for commands with control-R, etc.
6107 history filename NAME: NAME is where the gdb command history
6108 will be stored. The default is .gdb_history,
6109 or the value of the environment variable
6112 history size N: The size, in commands, of the command history. The
6113 default is 256, or the value of the environment variable
6116 history save on/off: If this value is set to ON, the history file will
6117 be saved after exiting gdb. If set to OFF, the
6118 file will not be saved. The default is OFF.
6120 history expansion on/off: If this value is set to ON, then csh-like
6121 history expansion will be performed on
6122 command line input. The default is OFF.
6124 radix N: Sets the default radix for input and output. It can be set
6125 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6126 in the current radix, so "set radix 10" is always a no-op.
6128 height N: This integer value is the number of lines on a page. Default
6129 is 24, the current `stty rows'' setting, or the ``li#''
6130 setting from the termcap entry matching the environment
6133 width N: This integer value is the number of characters on a line.
6134 Default is 80, the current `stty cols'' setting, or the ``co#''
6135 setting from the termcap entry matching the environment
6138 Note: ``set screensize'' is obsolete. Use ``set height'' and
6139 ``set width'' instead.
6141 print address on/off: Print memory addresses in various command displays,
6142 such as stack traces and structure values. Gdb looks
6143 more ``symbolic'' if you turn this off; it looks more
6144 ``machine level'' with it on. Default is ON.
6146 print array on/off: Prettyprint arrays. New convenient format! Default
6149 print demangle on/off: Print C++ symbols in "source" form if on,
6152 print asm-demangle on/off: Same, for assembler level printouts
6155 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6158 * Support for Epoch Environment.
6160 The epoch environment is a version of Emacs v18 with windowing. One
6161 new command, ``inspect'', is identical to ``print'', except that if you
6162 are running in the epoch environment, the value is printed in its own
6166 * Support for Shared Libraries
6168 GDB can now debug programs and core files that use SunOS shared libraries.
6169 Symbols from a shared library cannot be referenced
6170 before the shared library has been linked with the program (this
6171 happens after you type ``run'' and before the function main() is entered).
6172 At any time after this linking (including when examining core files
6173 from dynamically linked programs), gdb reads the symbols from each
6174 shared library when you type the ``sharedlibrary'' command.
6175 It can be abbreviated ``share''.
6177 sharedlibrary REGEXP: Load shared object library symbols for files
6178 matching a unix regular expression. No argument
6179 indicates to load symbols for all shared libraries.
6181 info sharedlibrary: Status of loaded shared libraries.
6186 A watchpoint stops execution of a program whenever the value of an
6187 expression changes. Checking for this slows down execution
6188 tremendously whenever you are in the scope of the expression, but is
6189 quite useful for catching tough ``bit-spreader'' or pointer misuse
6190 problems. Some machines such as the 386 have hardware for doing this
6191 more quickly, and future versions of gdb will use this hardware.
6193 watch EXP: Set a watchpoint (breakpoint) for an expression.
6195 info watchpoints: Information about your watchpoints.
6197 delete N: Deletes watchpoint number N (same as breakpoints).
6198 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6199 enable N: Re-enables watchpoint number N (same as breakpoints).
6202 * C++ multiple inheritance
6204 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6207 * C++ exception handling
6209 Gdb now supports limited C++ exception handling. Besides the existing
6210 ability to breakpoint on an exception handler, gdb can breakpoint on
6211 the raising of an exception (before the stack is peeled back to the
6214 catch FOO: If there is a FOO exception handler in the dynamic scope,
6215 set a breakpoint to catch exceptions which may be raised there.
6216 Multiple exceptions (``catch foo bar baz'') may be caught.
6218 info catch: Lists all exceptions which may be caught in the
6219 current stack frame.
6222 * Minor command changes
6224 The command ``call func (arg, arg, ...)'' now acts like the print
6225 command, except it does not print or save a value if the function's result
6226 is void. This is similar to dbx usage.
6228 The ``up'' and ``down'' commands now always print the frame they end up
6229 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6230 frames without printing.
6232 * New directory command
6234 'dir' now adds directories to the FRONT of the source search path.
6235 The path starts off empty. Source files that contain debug information
6236 about the directory in which they were compiled can be found even
6237 with an empty path; Sun CC and GCC include this information. If GDB can't
6238 find your source file in the current directory, type "dir .".
6240 * Configuring GDB for compilation
6242 For normal use, type ``./configure host''. See README or gdb.texinfo
6245 GDB now handles cross debugging. If you are remotely debugging between
6246 two different machines, type ``./configure host -target=targ''.
6247 Host is the machine where GDB will run; targ is the machine
6248 where the program that you are debugging will run.